add a troubleshooting doc

[dluc]

Since WSL doesn't come with python3 preinstalled, I suspect some people will stumble on the usual python setup issues:

• How to install python in WSL (Ubuntu):

  • sudo apt update
  • sudo apt install python3
  • sudo apt install python-is-python3

• How to install pip module:

  • sudo apt update
  • sudo apt install python3-pip

All at once: sudo apt update && sudo apt install python3 python-is-python3 python3-pip

If there's a troubleshooting doc, might be worth adding something on this note.

[ryanvolum]

We don't currently have a troubleshooting doc, but it's not a bad idea. @codehruv, what do you think of adding one?

[codehruv]

Yes a troubleshooting doc is a great idea. I can own it for now

[dluc]

I hope we can cover Python also considering some old distros, such as Ubuntu 18 (not too old in fact) where Codex CLI won't run because the latest version is Python 3.6.9 and Codex CLI requires 3.7.1.