Update User-Installed Apps Docs for GA (#6958)

* update user install docs

* add 5 max followup callout

* add change log

* pass through application

* remove lingering preview labels

* update wording in tutorial

* update defaults

* api update

* wrong wording oop

* Update docs/Change_Log.md

Co-authored-by: vee <vendicated@riseup.net>

* Update docs/resources/Application.md

Co-authored-by: vee <vendicated@riseup.net>

---------

Co-authored-by: vee <vendicated@riseup.net>

docs/Change_Log.md

@@ -1,5 +1,37 @@
 # Change Log
 
+## User-Installed Apps General Availability
+
+#### June 27, 2024
+
+> danger
+> This entry includes breaking changes
+
+Back in March, we announced [the beta for user-installed apps](#DOCS_CHANGE_LOG/userinstallable-apps-preview). After listening and making updates based on feedback from developers and modmins, we're excited to announce that user-installed apps are now considered generally available and can be used in all servers (regardless of size).
+
+With this update, there are a few API and behavioral updates for user-installed apps.
+
+###### API Updates
+
+- `user_id` has been removed from the `interaction_metadata` field on messages. Instead, you can use the `id` field in the nested `user` object. See the [Message Interaction Metadata Object](#DOCS_RESOURCES_CHANNEL/message-interaction-metadata-object) for details.
+- User-installed apps are now limited to creating a maximum of 5 [follow-ups](#DOCS_INTERACTIONS_RECEIVING_AND_RESPONDING/followup-messages) when responding to interactions. This only affects the [Create Followup Message endpoint](#DOCS_INTERACTIONS_RECEIVING_AND_RESPONDING/create-followup-message), and apps installed to the server are unaffected.
+- On [Interactions](#DOCS_INTERACTIONS_RECEIVING_AND_RESPONDING/interaction-object-interaction-structure), the value of `authorizing_integration_owners` is now correctly serialized as a string. Previously, the `"0"` value was incorrectly serialized as a number.
+- `app_permissions` on [Interactions](#DOCS_INTERACTIONS_RECEIVING_AND_RESPONDING/interaction-object-interaction-structure) now correctly represents the permissions for user-installed apps. Previously, the value was incorrect for user-installed apps.
+- Updating a message can result in a `400` response if the content of the message was blocked by AutoMod, which may be particularly important for [deferred messages](#DOCS_INTERACTIONS_RECEIVING_AND_RESPONDING/responding-to-an-interaction).
+- Interaction responses are no longer forced to be ephemeral for servers with over 25 members.
+
+###### New `Use External Apps` Permission
+
+A new [`USE_EXTERNAL_APPS` (`1 << 50`) permission](#DOCS_TOPICS_PERMISSIONS/permissions-bitwise-permission-flags) was added, and is enabled for servers by default. The new permission lets modmins control whether user-installed apps can post public replies in a server. If `Use External Apps` is disabled and your app is *not* installed to the server, your app’s responses will be ephemeral for the end user.
+
+Read more in the [Moderating Apps on Discord Help Center article](https://support.discord.com/hc/en-us/articles/23957313048343-Moderating-Apps-on-Discord#h_01HZQQQEADYVN2CM4AX4EZGKHM).
+
+###### Updated Defaults for New Apps
+
+- Newly-created apps now default to having both "User Install" *and* "Guild Install" [installation contexts](#DOCS_RESOURCES_APPLICATION/installation-context) enabled. This can be updated in the **Installation** tab in an [app's settings](https://discord.com/developers/applications).
+- Newly-created apps now default to using the "Discord Provided Link" [install link](#DOCS_RESOURCES_APPLICATION/install-links). This can be updated in the **Installation** tab in an [app's settings](https://discord.com/developers/applications).
+- If Discord Provided Link is selected as the install link type, `application.commands` scope is added to both installation contexts.
+
 ## Premium Apps: New Premium Button Style & Deep Linking URL Schemes
 
 #### June 17, 2024
@@ -76,9 +108,6 @@ You can find the export at the bottom of the `Monetization → Analytics` tab of
 
 #### March 18, 2024
 
-> preview
-> User-installable apps are currently in preview. During the preview, there are major [limitations and known bugs](#DOCS_CHANGE_LOG/march-18-2024-limitations-and-known-issues), and API details are subject to change.
-
 Apps can now be installed to users—making them easier to install, discover, and access across Discord. User-installed apps can be used across all of a user's servers, within their (G)DMs, and in DMs with the app's bot user.
 
 When creating or updating your app, you can choose which installation types your app supports on the **Installation** page in your [app's settings](https://discord.com/developers/applications). To quickly get started, you can follow the new [Developing a User-Installable App tutorial](#DOCS_TUTORIALS_DEVELOPING_A_USER_INSTALLABLE_APP) or read details about the new changes below.