ERROR: Unable to locate a modulefile for 'GPSInput'

Hi,

I was trying to use the modules you released on the [official website](https://ardupilot.org/mavproxy/docs/modules/index.html), so I followed the [developer's guide](https://ardupilot.org/mavproxy/docs/development/mavdevenvlinux.html) to install MAVProxy and ran the command `python setup.py build install --user`. I think the installation was successful because the output message from the terminal showed
```
Using /home/pi/.local/lib/python3.9/site-packages
Finished processing dependencies for MAVProxy==1.8.65
```
However, when I ran `Module load GPSInput`,
I got the error `ERROR: Unable to locate a modulefile for 'GPSInput'`

I also used `module avail` to see what modules are available to load. I got the below message
```
--------------------------------- /usr/share/modules/modulefiles ----------------------------------
dot module-git module-info modules null use.own

Key:
modulepath
```
It showed that MAVProxy was not under the folder of `modulefiles`.
I am wondering whether I missed some installation steps that caused this problem.
How do I fix the problem? I am looking forward to seeing your reply!

Best,
jiahau

Start with the MAVProxy module documentation and the Linux development guide linked in the report, then inspect setup.py and the GPSInput module-loading entry point. Reproduce the installation with `python setup.py build install --user` and `Module load GPSInput`, comparing it with `module avail`. Done means the documented installation makes GPSInput available without the modulefile error.

Written by the indexing model from the issue text.