Add Lagoon / Docker compose configuration

[Decipher]

Is your feature request related to a problem? Please describe.
As a contributor I want the Commerce demo to be hosted on Lagoon so that I can contribute to it.

Describe the solution you'd like

• Add Lagoon / Docker compose configuration

Describe alternatives you've considered
N/A

Additional context

• https://github.com/druxt/umami.demo.druxtjs.org/blob/develop/.lagoon.yml
• https://github.com/druxt/umami.demo.druxtjs.org/blob/develop/docker-compose.yml
• https://github.com/druxt/umami.demo.druxtjs.org/tree/develop/.docker

Update
I've encountered issues when running the install on Lagoon:

 [notice] Starting Drupal installation. This takes a while.

In InfoParserDynamic.php line 53:
                                                                               
  Unable to parse modules/contrib/commerce_demo/commerce_demo.info.yml yaml_p  arse(): scanning error encountered during parsing: found character that can not start any token (line 72, column 6), context while scanning for the next token (line 72, column 6)

I do not experience this issue when running the ddev start && ddev drupal-install process locally, which implies that something in the environment is different enough to cause this issue.