Update readme.

update 0.3 changelog

Build image on CI on Dockerfile changes in PR.

Update to Ruby 4.0 in tests. Ensure no warning around sync.

Avoid Bundler deprecation warning by using 'bundle config set path'

cleanup 2

cleanup

Improve shell suggestions.

Fix -C suggestion.

Remove redundant comments.

Migrate to new CLI structure.

Improve completion.

Fix specs.

Fix texts.

Reuse runtime.