Adding devcontainer definition

[aaronpowell]

This addresses #1095

• Added devcontainer feature definition at ext/devcontainer/
• Added tests for version
• Added GitHub Action to generate the devcontainer feature image
• Added GitHub Action to run tests

[ghost]

Hi @aaronpowell. Thank you for your interest in helping to improve the Azure Developer CLI experience and for your contribution. We've noticed that there hasn't been recent engagement on this pull request. If this is still an active work stream, please let us know by pushing some changes or leaving a comment. Otherwise, we'll close this out in 7 days.

[ghost]

Hi @aaronpowell. Thank you for your contribution. Since there hasn't been recent engagement, we're going to close this out. Feel free to respond with a comment containing "/reopen" if you'd like to continue working on these changes. Please be sure to use the command to reopen or remove the "no-recent-activity" label; otherwise, this is likely to be closed again with the next cleanup pass.

[ghost]

Hi @aaronpowell. Thank you for your contribution. Since there hasn't been recent engagement, we're going to close this out. Feel free to respond with a comment containing "/reopen" if you'd like to continue working on these changes. Please be sure to use the command to reopen or remove the "no-recent-activity" label; otherwise, this is likely to be closed again with the next cleanup pass.

[aaronpowell]

/reopen

[vhvb1989]

@karolz-ms , @jongio ping

[ellismg]

LGTM - One small note about setting the version here to something like 0.1.0 to start with, since we'll want to save 1.0.0 for once we have a little more confidence about these changes.

If @danieljurek is happy with the GitHub action stuff (I think he mentioned at standup today that publishing this from GitHub actions and to the ghcr associated with our repository is right thing to do) I think we can land this.

Thanks @aaronpowell and @hemarina for all your work here. I'm personally really excited for this to land and for us to have a real dev container feature and start using it across all our samples!

[ellismg]

LGTM - I agree with @danieljurek's feedback on the GitHub workflows, but once that's addressed happy to see this land and for us to start using it. Thanks again for all the hard work, everyone :-).

[savannahostrowski]

Chatted with Brigit - to add our Dev Container feature to the Remote Containers extension, we'll want to open a PR on
https://github.com/devcontainers/devcontainers.github.io/blob/gh-pages/_data/collection-index.yml. This will add it to the list of all community features. https://containers.dev/features

[hemarina]

/check-enforcer override

[hemarina]

Thank you all very much for the great work here. Feel free to let me know if there's any changes.