[📑 Docs]: Add content to "Where to Contribute" onboarding page

[me-pradeep]

What Dev Docs changes are you proposing?

I would like to contribute to AsyncAPI Docs by adding content to the "Where to Contribute" page under the community onboarding section.

Currently, this page is marked as under construction and does not provide guidance for new contributors. The proposed update would explain the different ways people can contribute to AsyncAPI, such as documentation, code, testing, design, and community support, along with basic guidance on how to get started.

This change would help improve onboarding for first-time contributors and make it easier for them to identify suitable areas to contribute based on their interests and skills.

Code of Conduct

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

Are you willing to work on this issue ?

Yes I am willing to submit a PR!