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

Conflicts:
- `README.md`:
  Upstream README has been changed, but we have a completely different one.
  Kept our `README.md`.
- `lib/sanitize_ext/sanitize_config.rb`:
  Upstream added support for more incoming HTML tags (a large subset of what
  glitch-soc accepts).
  Change the code style to match upstream's but otherwise do not change our
  code.
- `spec/lib/sanitize_config_spec.rb`:
  Upstream added support for more incoming HTML tags (a large subset of what
  glitch-soc accepts).
  Kept our version, since the tests are mostly glitch-soc's, except for cases
  which are purposefuly different.

config/environments/production.rb

@@ -128,6 +128,7 @@ Rails.application.configure do
     enable_starttls_auto: enable_starttls_auto,
     tls: ENV['SMTP_TLS'].presence && ENV['SMTP_TLS'] == 'true',
     ssl: ENV['SMTP_SSL'].presence && ENV['SMTP_SSL'] == 'true',
+    read_timeout: 20,
   }
 
   config.action_mailer.delivery_method = ENV.fetch('SMTP_DELIVERY_METHOD', 'smtp').to_sym