help: Update section header in 'restrict moving messages' for channel.

This commit updates the term 'stream' to 'channel' in the section
header 'Configure who can move messages to another stream' in
'/help/restrict-moving-messages'.

Also, references to this section has been updated.

help/moderating-open-organizations.md

@@ -31,7 +31,7 @@ problematic behavior.
   announcements](/help/configure-automated-notices#new-channel-announcements).
 * Restrict who can [add custom emoji](/help/custom-emoji#change-who-can-add-custom-emoji).
 * Restrict who can [move messages to another
-  stream](/help/restrict-moving-messages#configure-who-can-move-messages-to-another-stream),
+  channel](/help/restrict-moving-messages#configure-who-can-move-messages-to-another-channel),
   and set a [time
   limit](/help/restrict-moving-messages#set-a-time-limit-for-editing-topics) for
   editing topics.

help/move-content-to-another-channel.md

@@ -5,7 +5,7 @@ Organizations can [configure][configure-moving-permissions] which
 [roles](/help/roles-and-permissions) have permission to move messages between
 channels.
 
-[configure-moving-permissions]: /help/restrict-moving-messages#configure-who-can-move-messages-to-another-stream
+[configure-moving-permissions]: /help/restrict-moving-messages#configure-who-can-move-messages-to-another-channel
 
 To help others find moved content, you can have the [notification
 bot][notification-bot] send automated notices to the source topic, the

help/restrict-moving-messages.md

@@ -48,7 +48,7 @@ Permissions for moving messages between streams can be configured separately.
 
 {end_tabs}
 
-## Configure who can move messages to another stream
+## Configure who can move messages to another channel
 
 {start_tabs}
 

help/setting-up-zulip-for-a-class.md

@@ -170,13 +170,13 @@ how to assign roles and permissions for a class.
 - Set [who can edit the topic of any message](/help/restrict-moving-messages).
   (Recommended: (default) Members for small classes;
   Admins and moderators for large classes)
-- Set [who can move messages between streams][move-between-streams].
+- Set [who can move messages between channels][move-between-channels].
   (Recommended: Admins and moderators)
 - Set [who can create and manage user groups][user-group-permissions].
   (Recommended: Admins and moderators)
 
 [user-group-permissions]: /help/manage-user-groups#configure-who-can-create-and-manage-user-groups
-[move-between-streams]: /help/restrict-moving-messages#configure-who-can-move-messages-to-another-stream
+[move-between-channels]: /help/restrict-moving-messages#configure-who-can-move-messages-to-another-channel
 
 #### Recommended roles and permissions for a department
 
@@ -200,7 +200,7 @@ how to assign roles and permissions for a class.
   (Recommended: Admins and moderators)
 - Set [who can edit the topic of any message](/help/restrict-moving-messages).
   (Recommended: Admins and moderators)
-- Set [who can move messages between streams][move-between-streams].
+- Set [who can move messages between channels][move-between-channels].
   (Recommended: Admins and moderators)
 - Set [who can create and manage user groups][user-group-permissions].
   (Recommended: Admins and moderators)