release.md

Release process

• Update CHANGELOG with date and version
• Update Cargo.toml with version
• Update README.md and other images to point to github raw content at commit SHA1 of current HEAD
• cargo fmt --all
• cargo build
• cargo clippy --workspace --all-targets --all-features -- -D warnings
• cargo test
• cargo doc --no-deps
• cargo +nightly build (for docs.rs)