Add container dev environment, pkg instructions

[github-actions[bot]]

This pull request has been marked stale and will be closed soon without further activity. Please update the PR or respond to this comment if you're still interested in working on this.

[raylu]

would still like to get this merged

[roy7]

We can always change it more later if something here wasn't quite right. Better than leaving it stale. :) Thanks for the work @raylu