Build for arm64

This release builds for arm64.

Add --file, improve test coverage, update documentation

This is mostly a refactor release.

Changes:

• The exit status of check-auth is now non-zero when authentication fails
• All check commands now accept --file <path> in addition to reading from stdin.

Improve check title and summary

• Improve title and summary fields of check runs
• Add checkbridge version helper

Initial release, much alpha

This is the first binary release of checkbridge