Clarify that setting the Python version is a troubleshooting step

This groups all the Python setup description together, hopefully
simplifying the process of working out which sections of these
docs are needed.

Author: PeterJCLaw

simulator/setting_up_simulator.md

@@ -46,6 +46,31 @@ pip install -r competition-simulator-<version>/libraries.txt
 ~~~~~
 
 
+### Troubleshooting: setting your version of Python
+
+Sometimes Webots will not automatically detect your installed Python so we need to change it.
+When this happens Webots will print errors to its console and your robot will not move.
+
+You will need the full path to the version of Python that you want to use.
+This will vary based on the system you have.
+One way to find the path is by launching Python and running the following code:
+
+~~~~~ python
+import sys
+print(sys.executable)
+~~~~~
+
+Once you have the path you need to enter this into the Webots settings.
+
+To do this on Windows, open webots and go to the menu **Tools** &rarr; **Preferences** &rarr; **General** &rarr; **Python command** and enter the path in that box.
+Your Python path is likely similar to `C:\Users\<USERNAME>\AppData\Local\Programs\Python\Python311\python.exe` when using Python 3.11, where `<USERNAME>` is your login.
+
+On Mac you can set the path to the Python version to use via **Webots** &rarr; **Preferences** <kbd>⌘</kbd><kbd>,</kbd>.
+Your Python path is likely similar to `/Library/Frameworks/Python.framework/Versions/3.11/bin/python3` when using Python 3.11.
+
+If you're still having problems, ask for help in [Discord][discord].
+
+
 ## The world simulation {#world-simulation}
 
 The simulation for the SR2024 competition will be released at Kickstart.
@@ -77,31 +102,6 @@ On recent versions of macOS you may need to give Webots permission to access the
 </div>
 
 
-## Changing your version of Python
-
-Sometimes Webots will not automatically detect your installed Python so we need to change it.
-When this happens Webots will print errors to its console and your robot will not move.
-
-You will need the full path to the version of Python that you want to use.
-This will vary based on the system you have.
-One way to find the path is by launching Python and running the following code:
-
-~~~~~ python
-import sys
-print(sys.executable)
-~~~~~
-
-Once you have the path you need to enter this into the Webots settings.
-
-To do this on Windows, open webots and go to the menu **Tools** &rarr; **Preferences** &rarr; **General** &rarr; **Python command** and enter the path in that box.
-Your Python path is likely similar to `C:\Users\<USERNAME>\AppData\Local\Programs\Python\Python311\python.exe` when using Python 3.11, where `<USERNAME>` is your login.
-
-On Mac you can set the path to the Python version to use via **Webots** &rarr; **Preferences** <kbd>⌘</kbd><kbd>,</kbd>.
-Your Python path is likely similar to `/Library/Frameworks/Python.framework/Versions/3.11/bin/python3` when using Python 3.11.
-
-If you're still having problems, ask for help in [Discord][discord].
-
-
 ## Updates
 
 Occasionally, we may release an update to the simulation.