Update Cargo.toml

Update README for rcm-rs v0.8.0 (install, rename, LET-first docs)

docs: release note stub for v0.7.0

Update rust.yml

Update GPT.s

Create RCM.s

Create ARM.rs

Merge pull request #1 from drQedwards/drQedwards-patch-1

Add files via upload

Update README.md

Create README.md