Run Styleguide as npm executable module

[Winner95]

Types of changes

• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Proposed Changes

• now we can use styleguide via npx, which stops it from interfering with the dependencies of consumers

Please, confirm that:

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• My code requires separate test-version to release