ESPTOOL Rust Implementation

[robbym]

I wanted to learn more about the esptool and the ROM bootloader, and I like Rust, so I decided to implement esptool.py in Rust.
I only have communications up and running, and read_mac implemented, so I have a long way to go, but I wanted to post this now in case anyone wanted to help/learn about Rust/esptool.

Link to github: https://github.com/robbym/esptool-rs
PRs and issues welcome.

NOTE: I only have an esp32 so this currently only works with esp32s.
NOTE: Code is lacking documentation. Sorry.