Add Synapse module auto accept invite to rooms and direct messages (#3195)

* feat: auto-accept-invite module and docs

* fix: name typos and some forgot to adjust variables

* fix: accept only direct messages should work now and better wording

* changed: only_direct_messages variable naming

* feat: add logger, add synapse workers config

* Fix typo and add details about synapse-auto-acccept-invite

* Add newline at end of file

* Fix alignment

* Fix logger name for synapse_auto_accept_invite

The name of the logger needs to match the name of the Python module.

Ref: d673c67678/synapse_auto_accept_invite/__init__.py (L20)

* Add missing document start YAML annotation

* Remove trailing spaces

---------

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

README.md

@@ -165,6 +165,7 @@ Various services that don't fit any other category.
 | Name | Default? | Description | Documentation |
 | ---- | -------- | ----------- | ------------- |
 | [sliding-sync](https://github.com/matrix-org/sliding-sync)| x | Sliding Sync support for clients which require it (e.g. Element X) | [Link](docs/configuring-playbook-sliding-sync-proxy.md) |
+| [synapse_auto_accept_invite](https://github.com/matrix-org/synapse-auto-accept-invite) | x | A Synapse module to automatically accept invites. | [Link](docs/configuring-playbook-synapse-auto-accept-invite.md) |
 | [synapse_auto_compressor](https://github.com/matrix-org/rust-synapse-compress-state/#automated-tool-synapse_auto_compressor) | x | A cli tool that automatically compresses `state_groups` database table in background. | [Link](docs/configuring-playbook-synapse-auto-compressor.md) |
 | [synapse-simple-antispam](https://github.com/t2bot/synapse-simple-antispam) (advanced) | x | A spam checker module | [Link](docs/configuring-playbook-synapse-simple-antispam.md) |
 | [Matrix Corporal](https://github.com/devture/matrix-corporal) (advanced) | x | Reconciliator and gateway for a managed Matrix server | [Link](docs/configuring-playbook-matrix-corporal.md) |