help: Add a dedicated page on how to start a collaborative to-do list.

help/collaborative-to-do-lists.md

@@ -0,0 +1,12 @@
+# Collaborative to-do lists
+
+{!to-do-lists-intro.md!}
+
+## Examples
+
+{!to-do-lists-examples.md!}
+
+## Related articles
+
+* [Message formatting](/help/format-your-message-using-markdown)
+* [Polls](/help/create-a-poll)

help/format-your-message-using-markdown.md

@@ -26,7 +26,7 @@ whenever you need a reminder of the formatting syntax below.
 * [/me action messages](#me-action-messages)
 * [Global times](#global-times)
 * [Tables](#tables)
-* [To-do lists](#to-do-lists)
+* [Collaborative to-do lists](#collaborative-to-do-lists)
 * [Paragraphs and lines](#paragraphs-and-lines)
 
 ## Text emphasis
@@ -110,18 +110,11 @@ whenever you need a reminder of the formatting syntax below.
 
 {!tables-examples.md!}
 
-## To-do lists
+## Collaborative to-do lists
 
-Sending a message with the text `/todo` creates a simple collaborative
+{!to-do-lists-intro.md!}
-to-do list. Any user who can access the message can add tasks by
-entering the task's title and description and clicking "Add task". Once
-created, task titles and descriptions cannot be edited.
-
-Tasks can be marked (and unmarked) as completed by clicking the
-checkboxes on the left.
-
-![Markdown todo-lists](/static/images/help/markdown-todo.png)
 
+{!to-do-lists-examples.md!}
 
 ## Paragraphs and lines
 

help/include/sidebar_index.md

@@ -72,6 +72,7 @@
 * [Spoilers](/help/spoilers)
 * [/me action messages](/help/me-action-messages)
 * [Create a poll](/help/create-a-poll)
+* [Collaborative to-do lists](/help/collaborative-to-do-lists)
 * [Global times](/help/global-times)
 * [Start a video call](/help/start-a-call)
 

help/include/to-do-lists-examples.md

@@ -0,0 +1,20 @@
+### What you type
+
+```
+/todo
+```
+
+!!! warn ""
+
+    Any other content in a message starting with `/todo` will be ignored.
+
+### What it looks like
+
+After two tasks have been added to the shared to-do list:
+
+![Markdown todo-lists](/static/images/help/markdown-todo.png)
+
+!!! tip ""
+
+    Tasks can be marked (and unmarked) as completed by clicking the
+    checkboxes on the left.

help/include/to-do-lists-intro.md

@@ -0,0 +1,3 @@
+Zulip supports creating shared to-do lists where any user who can access the
+message can add tasks by entering the task's title and description, and clicking
+**Add task**. Once created, task titles and descriptions cannot be edited.