Merge branch 'feature/1631-redesign-mrf-configuration' into 'develop'

CHANGELOG.md

config/config.exs

config/description.exs

docs/configuration/cheatsheet.md

docs/configuration/mrf.md

docs/configuration/storing_remote_media.md

lib/pleroma/config/config_db.ex

lib/pleroma/config/deprecation_warnings.ex

lib/pleroma/web/activity_pub/mrf.ex

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

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

...0200323122421_mrf_config_move_from_instance_namespace.exs

test/config/deprecation_warnings_test.exs

test/tasks/config_test.exs

test/web/activity_pub/activity_pub_test.exs

test/web/activity_pub/mrf/mrf_test.exs

test/web/federator_test.exs

test/web/node_info_test.exs

test/workers/cron/purge_expired_activities_worker_test.exs