Bug: Default template do not follow the ruff and yamllint rules!

[ali-yz]

I had two issues when I pushed my newly created repo to test the workflows:

1. src/REPONAME/__init__.py: Ruff error: it doesn't have docstring
2. devenv.yaml: yamllint error: it did have two extra lines at the end. this is weird since it doesn't exist in the main inception repo!