added docs, added seperate service for database, pr comments

better path handling, fixed some mistakes

enable by default v2 api prefix for ma1sd

We can undo this once https://github.com/ma1uta/ma1sd/issues/44 gets
resolved.

Related to #508 (Github Pull Request).

Jitsi 4548-1 update

Typo STMP -> SMTP

Prevent 404s when Riot tries to retrieve domain-specific config.json

Riot unconditionally asks for a config.${document.domain}.json, c.f.
https://github.com/vector-im/riot-web/blame/develop/src/vector/getconfig.ts#L24

Document how to administer synapse database via tunneled web-frontend

Fixes #494 (Github Issue).

Add note about ask-become-pass

This flag is necessary for Ansible to ask for the sudo password when using the non-root option as documented in the `hosts` file. Otherwise, Ansible errors out with `missing sudo password`.

Fix typo in validation

This is mostly here to guard against problems happening
due to server migration and doing `chown -R matrix:matrix /matrix`.

Normally, the file is owned by `1000:1000`, as expected.

If ownership changes, Dimension could still start, but it will fail the
first time it tries to write to the database. Explicitly chowning
before startup guards against this.

Related to #485 and #486 (Github Pull Requests).
Also related to ccc7aaf0ce.

Dimension runs as the `node` user in the container (`1000:1000`).
It doesn't seem like we have a way around it. Thus, its configuration
must also be readable by that user (or group, in this case).

We don't really need to fail in such a spectactular way,
but it's probably good to do. It will only happen for people
who are defining their own user/group id, which is rare.

It seems like a good idea to tell them that this doesn't work
as they expect anymore and to ask them to remove these variables,
which otherwise give them a fake sense of hope.

Related to #486 (Github Pull Request).

Related to #485 (Github Pull Request).

Remove default UID/GID

If one runs the playbook with `--tags=setup-all`, it would have been
fine.

But running with a specific tag (e.g. `--tags=setup-riot-web`) would
have made that initialization be skipped, and the `matrix-riot-web` role
would fail, due to missing variables.

Added a documentation enhancement regarding external TURN server

Clarify domain of Dimension admin users in docs by using matrix_domain variable

Update coturn (4.5.1.1 -> 4.5.1.2)