Clarify that pip is for Python (& move to top) (#2526)

Clarify that pip is for Python (move to top)

Python is our most widely used interface, so should be extra easy to find

docs/user-guide/installation/index.md

@@ -69,6 +69,10 @@ graph LR
 
 [Build from source](./build_from_source.md)
 
+### Python via pip install
+
+[`pip install helics`](https://python.helics.org/)
+
 ### matHELICS install
 
 Installation instructions are available in the [matHELICS repository README](https://github.com/GMLC-TDC/matHELICS/blob/main/README.md)
@@ -77,10 +81,6 @@ Installation instructions are available in the [matHELICS repository README](htt
 
 [`pkg> add HELICS`](https://github.com/GMLC-TDC/HELICS.jl/blob/master/README.md)
 
-### pip install
-
-[`pip install helics`](https://python.helics.org/)
-
 ### jHELICS
 
 [Build from source](./build_from_source.md) with the [CMAKE option](./helics_cmake_options.md) `HELICS_BUILD_JAVA_INTERFACE=ON`