Add Protobuf Documentation

[georgi-l95]

Description

This PR adds documentation around the protobufs, explaining the gathering, generation and usage.

Related Issues

• Closes Document Protobuf usage and build process #33

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Changes

• Adds new document.

Reviewer Checklist

• The code follows the project's coding standards.
• New and existing unit tests pass locally with my changes.
• I have added necessary documentation (if applicable).
• I have confirmed that this change does not introduce any new security vulnerabilities.