check-imports v1.0

Breaking release that replaces Babel AST by TypeScript AST (with ts-morph) in order to work on any TS project.

• Breaking: Babel options has been removed completely but everything else remain the same.
• Fix: #1, #2 and #3.
  • In order to use private packages, you need to provide NPM_TOKEN env variable.
• Chore: Convert the project code into TypeScript.
• Chore: Turn the code into an ESM module.