chore: add use case issue form

[doc-jones]

Description

add Use Case Template form to make it easier for companies to share their use with us.

1st draft: comments and improvements welcomed

[netlify]

✔️ Deploy Preview for asyncapi-website ready!
Built without sensitive environment variables

🔨 Explore the source changes: bc9a564

🔍 Inspect the deploy log: https://app.netlify.com/sites/asyncapi-website/deploys/6188b22b311687000776cb5d

😎 Browse the preview: https://deploy-preview-456--asyncapi-website.netlify.app

[github-actions]

Welcome to AsyncAPI. Thanks a lot for creating your first pull request. Please check out our contributors guide useful for opening a pull request.
Keep in mind there are also other channels you can use to interact with AsyncAPI community. For more details check out this issue.

[derberg]

hmm I have a feeling we talked about it, and about moving it to spec or community repo, but I can't find any record 😅
where did we end up with the discussion? I just don't know if I should provide feedback here or wait for a PR to another repo first

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity 😴

It will be closed in 120 days if no further activity occurs. To unstale this pull request, add a comment with detailed explanation.

There can be many reasons why some specific pull request has no activity. The most probable cause is lack of time, not lack of interest. AsyncAPI Initiative is a Linux Foundation project not owned by a single for-profit company. It is a community-driven initiative ruled under open governance model.

Let us figure out together how to push this pull request forward. Connect with us through one of many communication channels we established here.

Thank you for your patience ❤️