/ci/lint should support include keyword in config file

The config file below will return license error on https://gitlab.com/ci/lint page. The project linked in include is public and the config file is publicly accessible.

include: 'https://gitlab.com/fatihacet/fatihacet.gitlab.io/raw/master/.gitlab-ci.yml'

rspec:
  script:
    - bundle exec rspec

Error: Your license does not allow to use 'include' keyword in CI/CD configuration file

Design

• Copy:

GitLab CI Linter has been moved

To validate your GitLab CI configurations, go to 'CI/CD → Pipelines' inside your project, and click on the "CI Lint" button.

• SVG: You can find it in gitlab-svgs.

/cc @ayufan @mayra-cabrera