website/docs: prepare changelog for 2021.4.3

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

website/docs/releases/v2021.4.md

@@ -62,6 +62,30 @@ slug: "2021.4"
 - web/admin: fix errors in user profile when non-superuser
 
 
+## Fixed in 2021.4.3
+
+- *: add model_name to TypeCreate API to distinguish between models sharing a component
+- api: fix CSRF error when using POST/PATCH/PUT in API Browser
+- api: make 401 messages clearer
+- api: mount outposts under outposts/instances to match flows
+- core: add parameter to output property mapping test result formatted
+- core: add superuser_full_list to applications list, shows all applications when superuser
+- core: fix Tokens being created with incorrect intent by default
+- outposts: don't run outpost_controller when no service connection is set
+- providers/oauth2: Set CORS Headers for token endpoint, check Origin header against redirect URLs
+- root: auto-migrate on startup, lock database using pg_advisory_lock
+- sources/oauth: add login with plex support
+- sources/oauth: fix redirect loop for source with non-configurable URLs
+- sources/oauth: save null instead of empty string for sources without configurable URLs
+- web/admin: add ability to add users to a group whilst creating a group
+- web/admin: fix default for codemirror
+- web/admin: fix group member table order
+- web/admin: fix non-matching provider type being selected when creating an OAuth Source
+- web/admin: fix provider type resetting when changing provider type
+- web/admin: fix undefined being shown when viewing application
+- web/admin: improve default selection for property-mappings
+
+
 ## Upgrading
 
 This release does not introduce any new requirements.