Add code documentation

[davidbtadokoro]

Context:

Right now, there is zero code documentation, both inside the source files and outside of them.

Proposal:

We must start documenting the code soon; otherwise, the project's complexity will grow, and this will turn into a big problem. Besides that, Rust seems to provide a robust infrastructure to generate external documentation like Javadoc (I think the name is Rustdoc, in this case 😅), so we should leverage this opportunity to evolve the project better.

Setup:

• Project branch: unstable
• Project commit hash: 75d37ac
• rustc version: 1.79.0
• cargo version: 1.79.0

[ivinjabraham]

I think we can leverage Deepwiki (https://deepwiki.com/kworkflow/patch-hub) to help out with this. It provides pretty accurate documentation but I think we still need a pair of human eyes to ensure it's not hallucinating.