The "New Years Resolution" release

Starting the new year with a big "tidy up" release.

The biggest change is a bump to the JSON schemas that are the core of this tool.
This means that it's possible that things that were previously (erroneously) allowed will now be caught, and vice versa.
Several bug reports (#14 by @brainstorm and #20 by @airtonix) and PRs (#16, thanks @satanabe1) appear to have been resolved just by this bump.
I've changed the way that the schemas are included, so future "bumps" should be minimally painful.

Two changes to releases:

• There are now pre-built binaries for Linux and macOS arm64 systems, and the asdf integration should correctly install them when asked (in theory; I don't have an arm64 machine to hand to test this).

• action-validator is now available on crates.io; this means that cargo install action-validator should work, if you've got a suitable Rust toolchain laying around.

The unmaintained ansi_term library has been removed as a transitive dependency (#17), which avoids any chance of problems in the future.

I've included an e2e test suite in the repo, which gets run on every push to GitHub.
It should provide early warning of problems that may crop up in the future, and provides a neat and simple way for people to provide PRs with examples of problems they find.