Update readme for recent tooling changes

This also reorganizes the "Specific tools" list, since they are all
configured in pyproject.toml now (only flake8 was not before, and
it was removed in favor of ruff in gitpython-developers#1862). In doing so, I've also
added brief parenthesized phrases to characterize what each of
these four tools is for, so readers don't have to look around as
much to understand most of the tooling GitPython has set up.

README.md

@@ -156,12 +156,14 @@ To test, run:
 pytest
 ```
 
-To lint, and apply automatic code formatting, run:
+To lint, and apply some linting fixes as well as automatic code formatting, run:
 
 ```sh
 pre-commit run --all-files
 ```
 
+This includes the linting and autoformatting done by Ruff, as well as some other checks.
+
 To typecheck, run:
 
 ```sh
@@ -170,18 +172,20 @@ mypy -p git
 
 #### CI (and tox)
 
-The same linting, and running tests on all the different supported Python versions, will be performed:
+Style and formatting checks, and running tests on all the different supported Python versions, will be performed:
 
 - Upon submitting a pull request.
 - On each push, *if* you have a fork with GitHub Actions enabled.
 - Locally, if you run [`tox`](https://tox.wiki/) (this skips any Python versions you don't have installed).
 
 #### Configuration files
 
-Specific tools:
+Specific tools are all configured in the `./pyproject.toml` file:
 
-- Configurations for `mypy`, `pytest`, `coverage.py`, and `black` are in `./pyproject.toml`.
-- Configuration for `ruff` is in the `pyproject.toml` file.
+- `pytest` (test runner)
+- `coverage.py` (code coverage)
+- `ruff` (linter and formatter)
+- `mypy` (type checker)
 
 Orchestration tools: