[Feature]: Handle linting of root folder files via o3r/eslint-config

[malek-benazzouz]

Context

Today, if we setup eslint via ng add @o3r/eslint-config in an o3r generated monorepo, the linter is configured to run on the app and lib files, but the files in the root folder (such as the root /jest.config.js file) are not linted, because no config exists for the root folder files.

This also causes, as a side effect, a discrepancy between the files linted by the CI, by lint-staged, and by the IDE:

1. CI: if you run npm run lint, files in the root folder are not linted.
2. lint-staged: if you run the pre-commit hooks on a root folder file, lint-staged script will lint this file.
3. IDE: lint issues in the root folder files will be raised by your IDE.

Proposal

Today, the linting of apps/libs is handled via the script "lint": "lerna run lint".

We could add to this command a parallel or subsequent process that runs eslint ./*.* to lint the root files. However, the command output will not look as readable as with the lerna command only, which may deteriorate the dev exp.

Any better suggestion is welcome.