Note that the init script can be run from Git Bash

This is probably the *only* way anyone should run that script on
Windows, but I don't know of specific bad things that happen if it
is run in some other way, such as with WSL bash, aside from messing
up line endings, which users are likely to notice anyway.

This commit also clarifies the instructions by breaking up another
paragraph that really represented two separate steps.

README.md

@@ -79,13 +79,17 @@ cd GitPython
 ./init-tests-after-clone.sh
 ```
 
+On Windows, `./init-tests-after-clone.sh` can be run in a Git Bash shell.
+
 If you are cloning [your own fork](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/about-forks), then replace the above `git clone` command with one that gives the URL of your fork. Or use this [`gh`](https://cli.github.com/) command (assuming you have `gh` and your fork is called `GitPython`):
 
 ```bash
 gh repo clone GitPython
 ```
 
-Having cloned the repo, create and activate your [virtual environment](https://docs.python.org/3/tutorial/venv.html). Then make an [editable install](https://pip.pypa.io/en/stable/topics/local-project-installs/#editable-installs):
+Having cloned the repo, create and activate your [virtual environment](https://docs.python.org/3/tutorial/venv.html).
+
+Then make an [editable install](https://pip.pypa.io/en/stable/topics/local-project-installs/#editable-installs):
 
 ```bash
 pip install -e ".[test]"