Add possibility to select gpu by line number

[Tony763]

Hello,
firstly thank you for this awesome shell. It really saved me some stress.
As I travel between two desks with my notebook, I also have two docks and GPUs.

To save some time, I edited your shell to add possibility to select GPU in setup also by line number, so I do not have to write down whole BusID.

Now it seems like this:

$ sudo ./gswitch setup
Which of these cards is your eGPU?
Nr: 0 BusID: 00:02.0 VGA compatible controller: Intel Corporation Iris Plus Graphics G7 (rev 07)
Nr: 1 BusID: 03:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon Pro WX 7100]
Please type in the BusID, e.g: 00:02.0 or line number