Reference: https://ansible-lint.readthedocs.io/en/latest/default_rules/#var-naming

We don't really fix these, but just suppress them,
because they're like that intentionally.

We try to name variables in a way that is consistent with the
configuration key they control. If the upstream component uses
camelCase, we also need to include camelCase in the variable name.

One that doesn't trip up ansible-lint, causing `load-failure` errors.

Reference: https://ansible-lint.readthedocs.io/en/latest/default_rules/#var-spacing

Reference: https://ansible-lint.readthedocs.io/en/latest/default_rules/#no-changed-when

Reference: https://ansible-lint.readthedocs.io/en/latest/default_rules/#git-latest

Our variable naming is not necessarily consistent across roles.
I've tried to follow the naming conventions of each individual role.
All new variables are suffixed with `_version`, but the prefix may be
somewhat different.

Reference: https://ansible-lint.readthedocs.io/en/latest/default_rules/#package-latest

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1939

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1931

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1931

This does 2 things:

- it fixes the syntax for `matrix_id`. Starting strings with `@` is
  invalid YAML, so such strings need to be wrapped in single or double
  quotes
- it makes use of the `matrix_domain` variable instead of hardcoding the
  domain name. This should be more and mistake-proof (typos or people
  mistaking their domain - matrix. vs base domain)

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1931

`|to_json` already adds the surrounding double-quotes for the string, so
adding them explicitly means we've got a double-quotes problem.

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1931

* Implement MSC 1929 Homeserver Admin Contact
Fixes #1612

For details to the proposed (not accepted yet) MSC, see:
https://github.com/matrix-org/matrix-spec-proposals/blob/hs/proposal-admin-contact-1/proposals/1929-admin-contact.md

* Implement feedback from PR #1931

* Implement feedback from PR #1931

* Fix mixed indentation

add ansible-lint; cleanup yamllint

update redis 6.2.6 -> 7.0.3

update sygnal 0.11.0 -> 0.12.0

update prometheus 2.36.2 -> 2.37.0

update nginx 1.21.6 -> 1.23.0

update grafana 9.0.2 -> 9.0.3

update dynamic dns 3.9.1-ls89 -> 3.9.1-ls92

update hydrogen 0.2.29 -> 0.2.33; sync config

fix mautrix-whatsapp config

add/unify 'Project source code URL' link across all roles

update buscarron from github -> gitlab

Update mautrix whatsapp 0.5.0 -> 0.6.0

project doesn't exist on github anymore

Update recommended Skype bridge in docs

Improvement over e4caf3fa81.

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1921