[📑 Docs]: Improve Contribution Flow Docs with a Full List of Contribution Types and Getting Started Info

[Aahil13]

What Dev Docs changes are you proposing?

As a follow up of #1964, we need to create or update a dedicated section (or subpage) in the Contribution Flow documentation listing:

• All recognized contribution types (code, docs, review, blogs, questions, ideas, community support, etc.)
• Their corresponding emoji keys
• What each type means
• How someone can get started contributing in that way (with relevant links, if applicable)

Once this list is available, we’ll update the “Recognizing Contributors” guide to point to it directly.

See here for more context.

Code of Conduct

• I agree to follow this project's Code of Conduct

[github-actions]

Welcome to AsyncAPI. Thanks a lot for reporting your first issue. Please check out our contributors guide and the instructions about a basic recommended setup 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.

[CBID2]

Can I work on this @thulieblack?