docs: document adding reply info

[quetzalliwrites]

As part of Google Season of Docs 2023 at AsyncAPI, we're going to write in-depth explanations of the different sections of an AsyncAPI document to avoid difficulties in implementing EDAs.

This task is part of the Docs EPIC: #1507.

For this issue, we'll cover:

• Adding reply info - Add info about a reply to a message, explain when one is when the reply is known and hard coded in the spec, but can be dynamic.

[quetzalliwrites]

assigned @TRohit20

[TRohit20]

Working on it!

[smoya]

I suggest we clarify in the description of this issue that this doc should be based on AsyncAPI Spec version 3.

[derberg]

@smoya reply is a new feature, so no way to base it on 2 😛

@TRohit20

• link to good intro about request-reply https://www.enterpriseintegrationpatterns.com/patterns/messaging/RequestReply.html
• examples in old pr
• knowledge sharing session recording https://fathom.video/share/uEDrQc9gxdkhwRcVk7qWrHtF7XjWsB3i

[smoya]

@smoya reply is a new feature, so no way to base it on 2 😛

I think it is completely worth mentioning anyway. It is not required to be an expert on this matter (AsyncAPI v3) to document, and I assume not all people will know about all features on v3. Just by mentioning this, any contributor will understand the context and know, at least, where to check for documentation or even how to formulate the right questions.