Decomplexify markup of macos installation box

No list with custom enumeration, just plain "one option after the
other".

Also update the Python version to not look stale.

docs/intro/installation.rst

@@ -247,44 +247,44 @@ Python's package manager <fom-macosx-pip>`.
    .. code-block:: text
 
      The script chardetect is installed in
-     '/Users/MYUSERNAME/Library/Python/3.7/bin' which is not on PATH.
+     '/Users/MYUSERNAME/Library/Python/3.11/bin' which is not on PATH.
      Consider adding this directory to PATH or, if you prefer to
      suppress this warning, use --no-warn-script-location.
 
    To fix this, add these paths to the ``$PATH`` environment variable.
-   You can either do this for your own user (1), or for all users of the computer (2)
-   (requires using ``sudo`` and authenticating with your computer's password):
+   You can do this for your own user account by adding something like the following
+   to the *profile* file of your shell (exchange the user name accordingly):
 
-   (1) Add something like (exchange the user name accordingly)
-
-       .. code-block:: bash
+   .. code-block:: bash
 
-          export PATH=$PATH:/Users/MYUSERNAME/Library/Python/3.7/bin
+      export PATH=$PATH:/Users/MYUSERNAME/Library/Python/3.11/bin
 
-       to the *profile* file of your shell. If you use a :term:`bash` shell, this may
-       be ``~/.bashrc`` or ``~/.bash_profile``, if you are using a :term:`zsh` shell,
-       it may be ``~/.zshrc`` or ``~/.zprofile``. Find out which shell you are using by
-       typing ``echo $SHELL`` into your terminal.
+   If you use a :term:`bash` shell, this may be ``~/.bashrc`` or
+   ``~/.bash_profile``, if you are using a :term:`zsh` shell, it may be
+   ``~/.zshrc`` or ``~/.zprofile``. Find out which shell you are using by
+   typing ``echo $SHELL`` into your terminal.
 
-   (2) Alternatively, configure it *system-wide*, i.e., for all users of your computer
-       by adding the the path ``/Users/MYUSERNAME/Library/Python/3.7/bin`` to the file
-       ``/etc/paths``, e.g., with the editor :term:`nano`:
+   Alternatively, you could configure it *system-wide*, i.e., for all users of
+   your computer by adding the path
+   ``/Users/MYUSERNAME/Library/Python/3.11/bin`` to the file ``/etc/paths``,
+   e.g., with the editor :term:`nano` (requires using ``sudo`` and authenticating
+   with your password):
 
-       .. code-block:: bash
+   .. code-block:: bash
 
-          sudo nano /etc/paths
+      sudo nano /etc/paths
 
-       The contents of this file could look like this afterwards (the last line was
-       added):
+   The contents of this file could look like this afterwards (the last line was
+   added):
 
-       .. code-block:: bash
+   .. code-block:: bash
 
-           /usr/local/bin
-           /usr/bin
-           /bin
-           /usr/sbin
-           /sbin
-           /Users/MYUSERNAME/Library/Python/3.7/bin
+       /usr/local/bin
+       /usr/bin
+       /bin
+       /usr/sbin
+       /sbin
+       /Users/MYUSERNAME/Library/Python/3.11/bin
 
 
 Linux: (Neuro)Debian, Ubuntu, and similar systems