help: Add polls section to "Message formating" article.

Creates an intro and an examples md file for the shared content
on the "Message formatting" article and "Polls" article.

help/create-a-poll.md

@@ -1,8 +1,6 @@
 # Polls
 
-Zulip makes it easy to create a poll. Polls in Zulip are collaborative, so
-anyone can add new options to a poll. However, only the creator of the poll can
-edit the question.
+{!polls-intro.md!}
 
 ## Create a poll
 
@@ -92,18 +90,7 @@ edit the question.
 
 ## Examples
 
-### What you type
-
-```
-/poll What did you drink this morning?
-Milk
-Tea
-Coffee
-```
-
-### What it looks like
-
-![Markdown polls](/static/images/help/markdown-polls.png)
+{!polls-examples.md!}
 
 ## Related articles
 

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

@@ -28,6 +28,7 @@ below.
 * [/me action messages](#me-action-messages)
 * [Global times](#global-times)
 * [Tables](#tables)
+* [Polls](#polls)
 * [Collaborative to-do lists](#collaborative-to-do-lists)
 * [Paragraph and section formatting](#paragraph-and-section-formatting)
 
@@ -168,6 +169,18 @@ below.
 
 {!tables-examples.md!}
 
+## Polls
+
+{!polls-intro.md!}
+
+{!polls-examples.md!}
+
+!!! tip ""
+
+    You can also use the **Add poll** (<i class="zulip-icon
+    zulip-icon-poll"></i>) button in the compose box to create a
+    poll. [Learn more](/help/create-a-poll).
+
 ## Collaborative to-do lists
 
 {!to-do-lists-intro.md!}

help/include/polls-examples.md

@@ -0,0 +1,12 @@
+### What you type
+
+```
+/poll What did you drink this morning?
+Milk
+Tea
+Coffee
+```
+
+### What it looks like
+
+![Markdown polls](/static/images/help/markdown-polls.png)

help/include/polls-intro.md

@@ -0,0 +1,3 @@
+Zulip makes it easy to create a poll. Polls in Zulip are collaborative, so
+anyone can add new options to a poll. However, only the creator of the poll can
+edit the question.