Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

Overall the playbook uses the expression "Add the following configuration to your `inventory/host_vars/matrix.DOMAIN/vars.yml` file:" with the heading "Adjusting the playbook configuration" for sections to explain what to be added as variables

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

All homeserver implementations have been updated to support this as
well.

It's just Jitsi that possibly doesn't work with anything other than `auth-secret`.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3191

Explicitly refer users to the relevant roles file so people know where to find the additional configuration options.

I was very surprised by the fact that a rather important configuration for coturn was "hidden" in the Hosts file, but not mentioned here. 

Therefore my suggestion is to explicitly mention it here, as I believe that is that natural for people to look.