DOC: Move python installation into optional section

README_SETUP.md

@@ -4,42 +4,8 @@
 
 ### How to install ###
 
-#### Linux ####
-
-Make sure that Python (at least version 3.8) and pip is installed, using your system tools and
-documentation.
-
-Then open a terminal and continue in the [Generic installation](#generic-installation) section.
-
-#### Windows ####
-
-If a Python distribution is not yet installed, we recommend Anaconda Python, which you can download
-for free from [https://www.anaconda.com](https://www.anaconda.com).  The "Anaconda Individual Edition" provides most of all
-packages you will ever need out of the box.  If you prefer, you may also install the leaner
-"Miniconda" installer, which allows you to install packages as you need them.
-
-After installation, open an Anaconda prompt from the Windows menu and continue in the [Generic
-installation](#generic-installation) section.
-
-#### MacOS ####
-
-If there is no Python 3 installed yet, there are two main ways to
-obtain it: Either get the binary package from
-[python.org](https://www.python.org/downloads/) or, for advanced
-users, install via [Homebrew](https://brew.sh/). After installation
-from python.org, it is recommended to also update the TLS certificates
-for Python (this requires administrator rights for your user):
-
-```sh
-# Replace this with your Python version number:
-cd /Applications/Python\ 3.9/
-
-# This needs administrator rights:
-sudo ./Install\ Certificates.command
-```
-
-After these steps, you may continue with the [Generic
-installation](#generic-installation).
+First ensure that python with at least version 3.8 is installed. Should this not be
+the case, you can use the [Installing python](#installing-python-) guide for your OS.
 
 #### Generic installation ####
 
@@ -80,6 +46,44 @@ A current list of the dependencies installed with this program as well as those
 the keywords can be found in `setup.py`s `setup_package()` method, in the `metadata` dictionary
 entries `install_requires` and `extras_require`.
 
+### Installing python ###
+
+#### Linux ####
+
+Make sure that Python (at least version 3.8) and pip is installed, using your system tools and
+documentation.
+
+Then open a terminal and continue in the [Generic installation](#generic-installation) section.
+
+#### Windows ####
+
+If a Python distribution is not yet installed, we recommend Anaconda Python, which you can download
+for free from [https://www.anaconda.com](https://www.anaconda.com).  The "Anaconda Individual Edition" provides most of all
+packages you will ever need out of the box.  If you prefer, you may also install the leaner
+"Miniconda" installer, which allows you to install packages as you need them.
+
+After installation, open an Anaconda prompt from the Windows menu and continue in the [Generic
+installation](#generic-installation) section.
+
+#### MacOS ####
+
+If there is no Python 3 installed yet, there are two main ways to
+obtain it: Either get the binary package from
+[python.org](https://www.python.org/downloads/) or, for advanced
+users, install via [Homebrew](https://brew.sh/). After installation
+from python.org, it is recommended to also update the TLS certificates
+for Python (this requires administrator rights for your user):
+
+```sh
+# Replace this with your Python version number:
+cd /Applications/Python\ 3.9/
+
+# This needs administrator rights:
+sudo ./Install\ Certificates.command
+```
+
+After these steps, you may continue with the [Generic installation](#generic-installation) section.
+
 ## Configuration ##
 
 The configuration is done using `ini` configuration files.  The content of these configuration files