Support emoji shortcodes in chat (#8455)

Completes: https://github.com/zed-industries/zed/issues/7299

Suggestions


https://github.com/zed-industries/zed/assets/53836821/2a81ba89-4634-4d94-8370-6f76ff3e9403

Automatically replacing shortcodes without using the completions (only
enabled when `message_editor` > `auto_replace_emoji_shortcode` is
enabled in the settings):


https://github.com/zed-industries/zed/assets/53836821/10ef2b4b-c67b-4202-b958-332a37dc088e






Release Notes:

- Added autocompletion for emojis in chat when typing emoji shortcodes
([#7299](https://github.com/zed-industries/zed/issues/7299)).
- Added support for automatically replacing emoji shortcodes in chat
(e.g. typing "👋" will be converted to "👋")

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

assets/settings/default.json

@@ -211,6 +211,11 @@
     // Default width of the channels panel.
     "default_width": 240
   },
+  "message_editor": {
+    // Whether to automatically replace emoji shortcodes with emoji characters.
+    // For example: typing `:wave:` gets replaced with `👋`.
+    "auto_replace_emoji_shortcode": true
+  },
   "notification_panel": {
     // Whether to show the collaboration panel button in the status bar.
     "button": true,