docs: Add user guide for previewing your message.

templates/zerver/help/index.md

@@ -46,7 +46,7 @@ as a “**realm**”.
 * Send a stream message
 * [Send a private message](/help/send-private-message)
 * [Format your message using Markdown](/help/format-your-message-using-markdown)
-* Preview your message before sending
+* [Preview your message before sending](/help/previewing-message)
 * [Add emoji](/help/add-emoji)
 * [Upload and share files](/help/upload-and-share-files)
 * Restore the last unsent message

templates/zerver/help/previewing-message.md

@@ -0,0 +1,9 @@
+# Previewing your message
+
+You can preview your message before you send it by clicking the **eye** (![eye](/static/images/help/eye.png)) icon.
+
+![Original content](/static/images/help/before-preview.png)
+
+![Previewed](/static/images/help/during-preview.png)
+
+To resume editing, click the **pencil and paper** (![pencil and paper](/static/images/help/pencil-paper.png)) icon that has replaced the eye icon.

templates/zerver/help/streams-and-private-messages.md

@@ -68,11 +68,8 @@ Clicking the **A**  (![A](/static/images/help/formatting.png)) icon will reveal
 
 If you accidentally delete your message by clicking the **x** (![x](/static/images/help/x.png)) icon in the upper right corner of your messaging box, you can restore your previous message by clicking a blue link labeled **Restore draft**, which appears between the **A** (![A](/static/images/help/formatting.png)) and **eye** (![eye](/static/images/help/eye.png)) icons.
 
-### Preview
-
-![Message preview](/static/images/help/preview.png)
-
-Clicking the **eye** (![eye](/static/images/help/eye.png)) icon will allow you to preview your message. To resume editing your message, click the **pencil and paper** (![pencil and paper](/static/images/help/pencil-paper.png)) icon that has replaced the eye icon.
+### Previewing your message
+Read about message previewing [here](/help/previewing-message).
 
 ### Press Enter to send
 Read about pressing enter to send [here](/help/press-enter-send).