help: Update emoji-and-emoticons to document changing emoji set.

templates/zerver/help/emoji-and-emoticons.md

@@ -3,21 +3,28 @@
 ## Add emoji to a message
 
 There are several ways to add emoji to a message: typing emoji codes,
-selecting from an emoji picker, using emoticons, or pasting unicode.
+selecting from an emoji picker, using emoticons, or pasting from another
+site.
 
 ### Type an emoji code
 
+{start_tabs}
+
 {!start-composing.md!}
 
 1. Type `:` followed by a few letters to open the emoji autocomplete. The
    letters don't have to be at the beginning of the emoji name; `:ppl` will
    match `:apple:`
 
+{end_tabs}
+
 If you don't know the code for an emoji, you can see what it's called in the
 emoji picker, or hover over the emoji in a message.
 
 ### Select from the emoji picker
 
+{start_tabs}
+
 {!start-composing.md!}
 
 1. Click the smiley face (<i class="fa fa-smile-o"></i>) icon at the
@@ -26,14 +33,41 @@ emoji picker, or hover over the emoji in a message.
 1. Select an emoji. You can type to search, use the arrow keys, or click on
    an emoji with your mouse.
 
+{end_tabs}
+
 ### Use emoticons
 
-[Enable emoticon translations](/help/enable-emoticon-translations), and then
-type away :). That link also has the list of supported emoticons.
+Use `:)` and `:/` instead of typing `:slight_smile:` and `:confused:`.
 
-### Paste unicode
+{start_tabs}
 
-Copying and pasting emoji from other apps generally works.
+{settings_tab|display-settings}
+
+1. Under **Emoji settings**, select **Convert emoticons before sending**.
+
+{end_tabs}
+
+The list of supported emoticons is available
+[here](/help/enable-emoticon-translations).
+
+### Paste from another site
+
+Copying and pasting emoji from other sites generally works. Email us at
+support@zulipchat.com if you find a site where it doesn't!
+
+## Change your emoji set
+
+Your emoji set determines how you see emoji. It has no effect on the emoji
+you send.
+
+{start_tabs}
+
+{settings_tab|display-settings}
+
+1. Under **Emoji settings**, select **Google modern**, **Google classic**,
+   or **Twitter**.
+
+{end_tabs}
 
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