[RFC] Improve website https://rustpython.github.io/

[stefnotch]

I wanted to try running yt-dlp using RustPython.
So I headed to the homepage and saw some installation instructions. Lovely!

Except, now what?
There are only online demos after that and the documentation doesn't tell me anything.

The answer was to look at the GitHub Readme. It'd be lovely if the website had some more info, like
"Now you can run RustPython by entering rustpython into the shell. e.g. rustpython -m demo.py"

[DimitrisJim]

Hm, well the idea in general is you should be able use the rustpython binary as you would use python. The docs for Python should equally apply here. I think a small note to that effect would be a good idea though.