Merge branch 'develop' into 'docs/add-clients-to-ex_doc'

.credo.exs

.gitlab-ci.yml

config/config.exs

config/dev.exs

docs/Clients.md

docs/Differences-in-MastodonAPI-Responses.md

docs/config.md

lib/pleroma/plugs/http_security_plug.ex

lib/pleroma/uploaders/mdii.ex

lib/pleroma/user.ex

lib/pleroma/user/welcome_message.ex

lib/pleroma/web/activity_pub/activity_pub.ex

lib/pleroma/web/activity_pub/mrf/hellthread_policy.ex

lib/pleroma/web/activity_pub/transmogrifier.ex

lib/pleroma/web/activity_pub/views/user_view.ex

lib/pleroma/web/mastodon_api/views/status_view.ex

lib/pleroma/web/media_proxy/media_proxy.ex

lib/pleroma/web/oauth/app.ex

lib/pleroma/web/oauth/authorization.ex

lib/pleroma/web/oauth/oauth_controller.ex