test: fix DOM tests, create-cli test

[nobkd]

TODO:

• rebase on dev
• fixing DOM tests (wrapped main content with article tag)
• find reason for DOMException: This element has no parent node. (was mounting components twice)

Other:

• simplify running tests
  • with Node: npm test or bun run test
  • with Bun: bun test
  • allow testing single package (when located at a sub-package's root)
• update checkout & bun action version

[nobkd]

now based on #312

[nobkd]

Is ready for review.

Includes also changes to create cli command.

Will probably have to check if -C automatically creates the dir
Edit: it doesn't. Will have to ensure dir exists beforehand.

[tipiirai]

Awesome work again!