Issues and Pull Requests were not migrated to the new
organization/repository, so `matrix-org/synapse/pull` and
`matrix-org/synapse/issues` references were kept as-is.

`matrix-org/synapse-s3-storage-provider` references were also kept,
as that module still continues living under the `matrix-org` organization.

This patch mainly aims to change documentation-related things, not actual
usage in full yet. For polish that, another more comprehensive patch is coming later.

* add auto join option to dendrite config

* added   auto_join_rooms: variable

* added "configuring dendrite" entry

* created dendite configuration documentation

* fixed config path

* Update docs/configuring-playbook-dendrite.md

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

* Update docs/configuring-playbook-dendrite.md

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

* Update docs/configuring-playbook-dendrite.md

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

* Update docs/configuring-playbook-dendrite.md

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

* Update docs/configuring-playbook-dendrite.md

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

* Update roles/custom/matrix-dendrite/defaults/main.yml

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

* correction

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