Using `.pre-commit-config` as a linter and test link check

I guess pre-commit is a good suggestion to let the project clean, and also check the new PRs if they correspond to the linting rules.

For example:

• I use https://github.com/pre-commit/pre-commit-hooks for checking:

hooks:
          - id: check-merge-conflict
          - id: check-added-large-files
          - id: check-ast
          - id: check-symlinks
          - id: trailing-whitespace
          - id: check-json
          - id: debug-statements
          - id: pretty-format-json

• For sorting imports, I use https://github.com/PyCQA/isort with the black profile.
• I use https://gitlab.com/pycqa/flake8 also for applying all style rules.

I will try to describe this issue in a PR.

The issue proposes a .pre-commit-config using pre-commit-hooks, isort with the black profile, and flake8; begin by checking the repository's current lint and test workflow. Done means the agreed hooks run successfully and new pull requests are checked against the project's linting rules.