Add table of contents to about page (#11885)

Move public domain blocks information to about page

app/views/about/more.html.haml

@@ -5,7 +5,7 @@
   = javascript_pack_tag 'public', integrity: true, crossorigin: 'anonymous'
   = render partial: 'shared/og'
 
-.grid-3
+.grid-4
   .column-0
     .public-account-header.public-account-header--no-bar
       .public-account-header__image
@@ -28,22 +28,57 @@
             = image_tag @instance_presenter.mascot&.file&.url || asset_pack_path('media/images/elephant_ui_plane.svg'), alt: ''
 
   .column-2
-    .landing-page__information.contact-widget
-      %p
-        %strong= t 'about.administered_by'
+    .contact-widget
+      %h4= t 'about.administered_by'
 
       = account_link_to(@instance_presenter.contact_account)
 
       - if @instance_presenter.site_contact_email.present?
-        %p.contact-widget__mail
-          %strong
-            = succeed ':' do
-              = t 'about.contact'
-          %br/
-          = mail_to @instance_presenter.site_contact_email, nil, title: @instance_presenter.site_contact_email
+        %h4
+          = succeed ':' do
+            = t 'about.contact'
+
+        = mail_to @instance_presenter.site_contact_email, nil, title: @instance_presenter.site_contact_email
 
   .column-3
     = render 'application/flashes'
 
-    .box-widget
-      .rich-formatting= @instance_presenter.site_extended_description.html_safe.presence || t('about.extended_description_html')
+    - if @contents.blank? && (!display_blocks? || @blocks&.empty?)
+      = nothing_here
+    - else
+      .box-widget
+        .rich-formatting
+          = @contents.html_safe
+
+          - if display_blocks? && !@blocks.empty?
+            %h2#unavailable-content= t('about.unavailable_content')
+
+            %p= t('about.unavailable_content_html')
+
+            - @blocks.each do |domain_block|
+              %p
+                %strong= "#{domain_block.domain}:"
+
+                - if domain_block.suspend?
+                  = t('about.unavailable_content_description.suspended')
+                - else
+                  = t('about.unavailable_content_description.silenced') if domain_block.silence?
+                  = t('about.unavailable_content_description.rejecting_media') if domain_block.reject_media?
+
+                - if display_blocks_rationale?
+                  %strong= t('about.unavailable_content_description.reason')
+                  = domain_block.public_comment
+
+  .column-4
+    %ul.table-of-contents
+      - @table_of_contents.each do |item|
+        %li
+          = link_to item.title, "##{item.anchor}"
+
+          - unless item.children.empty?
+            %ul
+              - item.children.each do |sub_item|
+                %li= link_to sub_item.title, "##{sub_item.anchor}"
+
+      - if display_blocks? && !@blocks.empty?
+        %li= link_to t('about.unavailable_content'), '#unavailable-content'