Add Mautic to DDEV quickstart docs

[RCheesley]

It would be awesome if we could add Mautic to the quickstart docs on the DDEV website:

https://ddev.readthedocs.io/en/stable/users/quickstart/

[favour-chibueze]

New Project

mkdir my-mautic-site && cd my-mautic-site
ddev config --project-type=php --docroot=public --create-docroot
ddev start
ddev launch

Existing Projects

git clone <my-mautic-repo> my-mautic-site
cd my-mautic-site
ddev config --project-type=php --docroot=public
ddev start
ddev composer install
ddev launch

@RCheesley, Will this work? Is there anything I can add to the documentation?

[RCheesley]

We do not need the ddev config commands because Mautic ships with a pre-made configuration, meaning you don't need to do any config. Just run ddev start.

The only case might be if their existing repo was not cloned down from mautic/mautic in the first place, in which case they would need to do ddev config. But I think we could perhaps add a note saying this assumes you've cloned from mautic/mautic, if not copy the .ddev folder from the repo first, which would mean you have all the configuration needed? What do you think?

Otherwise I think it looks OK, however for the new project you'll need to clone the repo first, I think - that step seems to be missing (in that case you'd be cloning mautic/mautic instead of their existing repo).