Update megalinter.yml (#16)

disable `VALIDATE_ALL_CODEBASE` because this is a small project and the errors aren't useful if it always fails

.github/workflows/megalinter.yml

@@ -89,6 +89,7 @@ jobs:
           #     github.event_name == 'push' &&
           #     contains(fromJSON('["refs/heads/main", "refs/heads/master"]'), github.ref)
           #   }}
+          VALIDATE_ALL_CODEBASE: false
 
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # ADD YOUR CUSTOM ENV VARIABLES HERE OR DEFINE THEM IN A FILE