Add external modules description

[jhelison]

Is your feature request related to a problem? Please describe.
Currently we have the description of the modules developed by Kiichain, but we are missing documentation for external modules that live on the chain

Describe the solution you'd like
Add documentation for:

• EVM
• ERC20
• FeeMarket
• Rate limiter

Describe alternatives you've considered
Looking at the code

Additional context
You can find references and original repo for the modules at the go.mod

[getcakedieyoungx]

Hi @jhelison! I have reviewed the external modules referenced in the go.mod, could you assign this issue to me?

I created documentation pages for each of the main modules (EVM, ERC20, FeeMarket, Rate Limiter) as requested.

Each page includes:

• A general description and objectives of the module
• Main function calls and queries (with usage context)
• Reference links to the original repositories and standards

Let me know if you’d like any additional details or examples for a specific module!