mwdd: Enable installing with mariadb
This adds the logic for the mysql service that for now
just uses a mariadb image from docker hub.
Eventually a followup will come to allow custom images to be used here.
Verified in github actions on addshore fork
You can see the steps needed to test this out in the test there.
Assuming you have mediawiki, composer installed with the correct settings
- mwcli mwdd create
- mwcli mwdd mysql create
- mwcli mwdd mediawiki install somesite mysql
Really should figure out how to best maintain the docs for this soon.