Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- README.md
  discarded upstream changes
- app/controllers/api/v1/bookmarks_controller.rb
  finally merged upstream, some code style fixes
  and slightly changed pagination code
- app/controllers/application_controller.rb
  changed upstream to always return HTML error pages
  slight conflict caused by theming code
- app/models/bookmark.rb
  finally merged upstream, no real conflict
- spec/controllers/api/v1/bookmarks_controller_spec.rb
  finally merged upstream, slightly changed pagination code

spec/controllers/api/v1/accounts/credentials_controller_spec.rb

@@ -59,6 +59,19 @@ describe Api::V1::Accounts::CredentialsController do
         end
       end
 
+      describe 'with empty source list' do
+        before do
+          patch :update, params: {
+            display_name: "I'm a cat",
+            source: {},
+          }, as: :json
+        end
+
+        it 'returns http success' do
+          expect(response).to have_http_status(200)
+        end
+     end
+
       describe 'with invalid data' do
         before do
           note = 'This is too long. '