add changelog

Author: Rodentman87

docs/Change_Log.md

@@ -1,5 +1,15 @@
 # Change Log
 
+## Application Emoji
+
+#### July 18, 2024
+
+You can now upload emojis for your application in your [app's settings](https://discord.com/developers/applications) and use them as custom emojis anywhere on Discord.
+
+- Up to 2000 emojis per app
+- Support for user-installable apps
+- Can be [managed via the API](#DOCS_RESOURCES_EMOJI/create-application-emoji) with a bot token
+
 ## Activities Proxy CSP Update
 
 #### July 17, 2024