Three tier mapping application demo (example app templates)

[ryanj]

Hello,
My team has developed a Backstage workshop for Red Hat Summit 2023, and we were wondering if it would be useful to contribute our example demo application templates to this repo.

If these example application templates seem useful, let me know. I would be happy to queue up a PR for review.

Our workshop templates can be found under the scaffolder-templates folder here: https://github.com/redhat-scholars/backstage-workshop/

[schultzp2020]

@christophe-f

[christophe-f]

To avoid duplication (and potentially not in synced repos), I don't think we should have them here, but we could definitely mention the link in the README.