Add blueprinter_schema extension

[thisismydesign]

I created an extension and would like to add it to your readme

Checklist:

• I have updated the necessary documentation
• I have signed off all my commits as required by DCO
• My build is green

[lessthanjacob]

@thisismydesign Great to see a new extension here!

After discussing internally, we're going to be adding some copy to this part of the README in anticipation of more extensions being added in the future (and to be super clear about ownership boundaries).

I'll circle back here when that change is in place, and we can get your extension added!

[thisismydesign]

Thanks @lessthanjacob

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[thisismydesign]

@lessthanjacob Any update? :)

[lessthanjacob]

@thisismydesign Apologies for the exceptionally long delay here!

I have a PR open to rework the Extensions section, and I'll report back here when that's merged in!