docs: Detailed documentation

[hmrtn]

This (WIP) PR adds detailed documentation to Zeth. The updates aim to provide clearer context and more detailed explanations for developers.

TODO:

• guests

  • eth-block
    • main.rs

• host

  • main.rs

• lib

  • block_builder.rs
  • consts.rs
  • execution.rs
  • host
    • mpt.rs
    • provider
      • cached_rpc_provider.rs
      • file_provider.rs
      • rpc_provider.rs
    • provider_db.rs
  • mem_db.rs
  • validation.rs

• primitives

  • access_list.rs
  • block.rs
  • ethers.rs
  • keccak.rs
  • lib.rs
  • receipt.rs
  • revm.rs
  • signature.rs
  • transaction.rs
  • withdrawl.rs
  • trie
    • account.rs
    • mpt.rs

Draft: looking for early feedback - lmk if it missing anything, typos, or is too pedantic.

[hmrtn]

Did I understand this correctly?

[hashcashier]

So the first nibble of the first byte in the resulting vector encodes two pieces of information:

• If the encoded path is for a leaf or extension (2nd least significant bit in nibble)
• If the number of nibbles encoded in the path is even or odd (least significant bit in nibble)

The second nibble of the first byte is used to represent the first nibble in the slice only if the length of the slice is odd, otherwise that second nibble is set to zero and just considered as padding.

I don't think the description makes that distinction.

[hmrtn]

Closing this and opening new PRs to split up into smaller PRs and to avoid conflicts with latest refactor.