Use awesome-lint

[vordimous]

This PR fixes lint errors, adds a separate license file, and creates a PR job to lint addttions.

awesome-data-engineering % npx awesome-lint .
✖ Linting

  README.md:1:1
  ✖  1:1  The repository should have "awesome" as a GitHub topic       remark-lint:awesome-github
  ✖  1:1  The repository should have "awesome-list" as a GitHub topic  remark-lint:awesome-github
  ✖  1:1   License was not detected by GitHub                           remark-lint:awesome-github

  3 errors

[vordimous]

@igorbarinov I cannot add topics to this repo to satisfy the above lint rule. Once you do that, this PR can be merged.