Add Typescript types for some API objects (#26602)

app/serializers/rest/account_serializer.rb

@@ -4,6 +4,8 @@ class REST::AccountSerializer < ActiveModel::Serializer
   include RoutingHelper
   include FormattingHelper
 
+  # Please update `app/javascript/mastodon/api_types/accounts.ts` when making changes to the attributes
+
   attributes :id, :username, :acct, :display_name, :locked, :bot, :discoverable, :group, :created_at,
              :note, :url, :uri, :avatar, :avatar_static, :header, :header_static,
              :followers_count, :following_count, :statuses_count, :last_status_at

app/serializers/rest/custom_emoji_serializer.rb

@@ -3,6 +3,8 @@
 class REST::CustomEmojiSerializer < ActiveModel::Serializer
   include RoutingHelper
 
+  # Please update `app/javascript/mastodon/api_types/custom_emoji.ts` when making changes to the attributes
+
   attributes :shortcode, :url, :static_url, :visible_in_picker
 
   attribute :category, if: :category_loaded?

app/serializers/rest/relationship_serializer.rb

@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 class REST::RelationshipSerializer < ActiveModel::Serializer
+  # Please update `app/javascript/mastodon/api_types/relationships.ts` when making changes to the attributes
+
   attributes :id, :following, :showing_reblogs, :notifying, :languages, :followed_by,
              :blocking, :blocked_by, :muting, :muting_notifications,
              :requested, :requested_by, :domain_blocking, :endorsed, :note