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

Conflicts:
- app/javascript/mastodon/features/compose/components/compose_form.js
  Upstream cleaned up a bit, including on lines in which
  we replaced the hardcoded 500 character limit with a maxChar
  constant. Applied the changes while keeping maxChar instead of 500.
- app/javascript/packs/public.js
  Moved upstream's new animated avatar hover handling in
  app/javascript/core/public.js
- app/javascript/styles/fonts/montserrat.scss
  Upstream fixed local font name, applied those changes.
- app/javascript/styles/fonts/roboto.scss
  Upstream fixed local font name, applied those changes.
- lib/mastodon/version.rb
  Upstream made repo URL configurable, did the same, but
  default to glitch-soc

app/lib/proof_provider/keybase.rb

@@ -2,7 +2,7 @@
 
 class ProofProvider::Keybase
   BASE_URL = ENV.fetch('KEYBASE_BASE_URL', 'https://keybase.io')
-  DOMAIN   = ENV.fetch('KEYBASE_DOMAIN', Rails.configuration.x.local_domain)
+  DOMAIN   = ENV.fetch('KEYBASE_DOMAIN', Rails.configuration.x.web_domain)
 
   class Error < StandardError; end