Change about page to be mounted in the web UI (#19345)

config/locales/en.yml

@@ -2,41 +2,15 @@
 en:
   about:
     about_mastodon_html: 'The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!'
-    about_this: About
-    administered_by: 'Administered by:'
     api: API
     apps: Mobile apps
-    contact: Contact
     contact_missing: Not set
     contact_unavailable: N/A
     documentation: Documentation
     hosted_on: Mastodon hosted on %{domain}
-    instance_actor_flash: |
-      This account is a virtual actor used to represent the server itself and not any individual user.
-      It is used for federation purposes and should not be blocked unless you want to block the whole instance, in which case you should use a domain block.
     privacy_policy: Privacy Policy
-    rules: Server rules
-    rules_html: 'Below is a summary of rules you need to follow if you want to have an account on this server of Mastodon:'
     source_code: Source code
-    status_count_after:
-      one: post
-      other: posts
-    status_count_before: Who published
-    unavailable_content: Moderated servers
-    unavailable_content_description:
-      domain: Server
-      reason: Reason
-      rejecting_media: 'Media files from these servers will not be processed or stored, and no thumbnails will be displayed, requiring manual click-through to the original file:'
-      rejecting_media_title: Filtered media
-      silenced: 'Posts from these servers will be hidden in public timelines and conversations, and no notifications will be generated from their users interactions, unless you are following them:'
-      silenced_title: Limited servers
-      suspended: 'No data from these servers will be processed, stored or exchanged, making any interaction or communication with users from these servers impossible:'
-      suspended_title: Suspended servers
-    unavailable_content_html: Mastodon generally allows you to view content from and interact with users from any other server in the fediverse. These are the exceptions that have been made on this particular server.
-    user_count_after:
-      one: user
-      other: users
-    user_count_before: Home to
+    title: About
     what_is_mastodon: What is Mastodon?
   accounts:
     choices_html: "%{name}'s choices:"

config/routes.rb

@@ -487,7 +487,9 @@ Rails.application.routes.draw do
       resource :instance, only: [:show] do
         resources :peers, only: [:index], controller: 'instances/peers'
         resources :rules, only: [:index], controller: 'instances/rules'
+        resources :domain_blocks, only: [:index], controller: 'instances/domain_blocks'
         resource :privacy_policy, only: [:show], controller: 'instances/privacy_policies'
+        resource :extended_description, only: [:show], controller: 'instances/extended_descriptions'
         resource :activity, only: [:show], controller: 'instances/activity'
       end
 
@@ -642,8 +644,8 @@ Rails.application.routes.draw do
 
   get '/web/(*any)', to: 'home#index', as: :web
 
-  get '/about',        to: redirect('/')
-  get '/about/more',   to: 'about#more'
+  get '/about',        to: 'about#show'
+  get '/about/more',   to: redirect('/about')
 
   get '/privacy-policy', to: 'privacy#show', as: :privacy_policy
   get '/terms',          to: redirect('/privacy-policy')