api-docs: Add changes section in construct a narrow article.

Adds a header to the section of changes notes about new and
deprecated narrow filters, so that it's easier to directly
link to the relevant content in the construct a narrow article
from the main API changelog and endpoint documentation.

api_docs/changelog.md

@@ -43,7 +43,7 @@ format used by the Zulip server that they are interacting with.
   [`GET /messages/matches_narrow`](/api/check-messages-match-narrow),
   [`POST /messages/flags/narrow`](/api/update-message-flags-for-narrow),
   [`POST /register`](/api/register-queue):
-  Added support for a new [search/narrow filter](/api/construct-narrow),
+  Added support for a new [search/narrow filter](/api/construct-narrow#changes),
   `with`, which returns messages in the same channel and topic as that
   of the operand of filter, with the first unread message as anchor.
 
@@ -105,7 +105,7 @@ format used by the Zulip server that they are interacting with.
   [`GET /messages/matches_narrow`](/api/check-messages-match-narrow),
   [`POST /messages/flags/narrow`](/api/update-message-flags-for-narrow),
   [`POST /register`](/api/register-queue):
-  Added a new [search/narrow filter](/api/construct-narrow),
+  Added a new [search/narrow filter](/api/construct-narrow#changes),
   `is:followed`, matching messages in topics that the current user is
   [following](/help/follow-a-topic).
 
@@ -254,7 +254,7 @@ format used by the Zulip server that they are interacting with.
   [`GET /messages/matches_narrow`](/api/check-messages-match-narrow),
   [`POST /messages/flags/narrow`](/api/update-message-flags-for-narrow),
   [`POST /register`](/api/register-queue):
-  Added support for two [search/narrow filters](/api/construct-narrow)
+  Added support for two [search/narrow filters](/api/construct-narrow#changes)
   related to stream messages: `channel` and `channels`. The `channel`
   operator is an alias for the `stream` operator. The `channels`
   operator is an alias for the `streams` operator.
@@ -265,7 +265,7 @@ format used by the Zulip server that they are interacting with.
   [`GET /messages/matches_narrow`](/api/check-messages-match-narrow),
   [`POST /messages/flags/narrow`](/api/update-message-flags-for-narrow),
   [`POST /register`](/api/register-queue):
-  Added support for a new [search/narrow filter](/api/construct-narrow),
+  Added support for a new [search/narrow filter](/api/construct-narrow#changes),
   `has:reaction`, which returns messages with at least one [emoji
   reaction](/help/emoji-reactions).
 
@@ -781,8 +781,8 @@ No changes; feature level used for Zulip 8.0 release.
   [`GET /messages/matches_narrow`](/api/check-messages-match-narrow),
   [`POST /messages/flags/narrow`](/api/update-message-flags-for-narrow),
   [`POST /register`](/api/register-queue):
-  For [search/narrow filters](/api/construct-narrow) with the `id`
-  operator, added support for encoding the message ID operand as either
+  For [search/narrow filters](/api/construct-narrow#message-ids) with the
+  `id` operator, added support for encoding the message ID operand as either
   a string or an integer. Previously, only string encoding was supported.
 
 **Feature level 193**
@@ -917,7 +917,7 @@ No changes; feature level used for Zulip 7.0 release.
   [`GET /messages/matches_narrow`](/api/check-messages-match-narrow),
   [`POST /messages/flags/narrow`](/api/update-message-flags-for-narrow),
   [`POST /register`](/api/register-queue):
-  Added support for three [search/narrow filters](/api/construct-narrow)
+  Added support for three [search/narrow filters](/api/construct-narrow#changes)
   related to direct messages: `is:dm`, `dm` and `dm-including`.
   The `dm` operator replaces and deprecates the `pm-with` operator.
   The `is:dm` filter replaces and deprecates the `is:private` filter.
@@ -2389,7 +2389,7 @@ No changes; feature level used for Zulip 3.0 release.
 * [`POST /register`](/api/register-queue): Added
   `realm_default_external_accounts` to endpoint response.
 * [`GET /messages`](/api/get-messages): Added support for
-  [search/narrow options](/api/construct-narrow) that use stream/user
+  [search/narrow options](/api/construct-narrow#changes) that use stream/user
   IDs to specify a message's sender, its stream, and/or its recipient(s).
 * [`GET /users`](/api/get-users): Added `include_custom_profile_fields`
   to request custom profile field data.

api_docs/construct-narrow.md

@@ -51,41 +51,44 @@ important optimization when fetching messages in certain cases (e.g.,
 when [adding the `read` flag to a user's personal
 messages](/api/update-message-flags-for-narrow)).
 
-**Changes**: In Zulip 9.0 (feature level 271), narrows gained support
+## Changes
+
+* In Zulip 9.0 (feature level 271), narrows gained support
   for a new `with` operator for linking to topics.
 
-In Zulip 9.0 (feature level 265), support was added for a
-new `is:followed` filter, matching messages in topics that the current
+* In Zulip 9.0 (feature level 265), support was added for a new
+  `is:followed` filter, matching messages in topics that the current
   user is [following](/help/follow-a-topic).
 
-In Zulip 9.0 (feature level 250), support was added for
-two filters related to stream messages: `channel` and `channels`. The
-`channel` operator is an alias for the `stream` operator. The `channels`
+* In Zulip 9.0 (feature level 250), support was added for two filters
+  related to stream messages: `channel` and `channels`. The `channel`
+  operator is an alias for the `stream` operator. The `channels`
   operator is an alias for the `streams` operator. Both `channel` and
   `channels` return the same exact results as `stream` and `streams`
   respectively.
 
-In Zulip 9.0 (feature level 249), support was added for a new filter,
+* In Zulip 9.0 (feature level 249), support was added for a new filter,
   `has:reaction`, which returns messages that have at least one [emoji
   reaction](/help/emoji-reactions).
 
-In Zulip 7.0 (feature level 177), support was added
-for three filters related to direct messages: `is:dm`, `dm` and
-`dm-including`. The `dm` operator replaced and deprecated the
-`pm-with` operator. The `is:dm` filter replaced and deprecated
-the `is:private` filter. The `dm-including` operator replaced and
-deprecated the `group-pm-with` operator.
+* In Zulip 7.0 (feature level 177), support was added for three filters
+  related to direct messages: `is:dm`, `dm` and `dm-including`. The
+  `dm` operator replaced and deprecated the `pm-with` operator. The
+  `is:dm` filter replaced and deprecated the `is:private` filter. The
+  `dm-including` operator replaced and deprecated the `group-pm-with`
+  operator.
 
-The `dm-including` and `group-pm-with` operators return slightly
+    * The `dm-including` and `group-pm-with` operators return slightly
       different results. For example, `dm-including:1234` returns all
       direct messages (1-on-1 and group) that include the current user
       and the user with the unique user ID of `1234`. On the other hand,
-`group-pm-with:1234` returned only group direct messages that included
-the current user and the user with the unique user ID of `1234`.
+      `group-pm-with:1234` returned only group direct messages that
+      included the current user and the user with the unique user ID of
+      `1234`.
 
-Both `dm` and `is:dm` are aliases of `pm-with` and `is:private`
-respectively, and return the same exact results that the deprecated
-filters did.
+    * Both `dm` and `is:dm` are aliases of `pm-with` and `is:private`
+      respectively, and return the same exact results that the
+      deprecated filters did.
 
 ## Narrows that use IDs
 

zerver/openapi/zulip.yaml

@@ -6266,7 +6266,8 @@ paths:
             subscribed to appropriate channels or use a shared history
             search narrow with this endpoint.
 
-            **Changes**: See changelog at [Construct a narrow](/api/construct-narrow).
+            **Changes**: See [changes section](/api/construct-narrow#changes)
+            of search/narrow filter documentation.
           content:
             application/json:
               schema:
@@ -7129,7 +7130,8 @@ paths:
                     optimization. Including that filter takes advantage of the fact that
                     the server has a database index for unread messages.
 
-                    **Changes**: See changelog at [Construct a narrow](/api/construct-narrow).
+                    **Changes**: See [changes section](/api/construct-narrow#changes)
+                    of search/narrow filter documentation.
                   type: array
                   items:
                     oneOf:
@@ -7550,7 +7552,8 @@ paths:
             A structure defining the narrow to check against. See how to
             [construct a narrow](/api/construct-narrow).
 
-            **Changes**: See changelog at [Construct a narrow](/api/construct-narrow).
+            **Changes**: See [changes section](/api/construct-narrow#changes)
+            of search/narrow filter documentation.
           content:
             application/json:
               schema:
@@ -22673,7 +22676,8 @@ components:
         See the `all_public_streams` parameter for how to process all
         public channel messages in an organization.
 
-        **Changes**: See changelog at [Construct a narrow](/api/construct-narrow).
+        **Changes**: See [changes section](/api/construct-narrow#changes)
+        of search/narrow filter documentation.
       type: array
       items:
         type: array