Add support for GS75 in readme and script

[Mostrapotski]

I tried the script with the GS65 model, it's working well on my GS75.

Steady colors are ok.

Using a preset is OK on most keys, except:
Ver num / * - + ENTER_KEY POINT_KEY and all num (0 1 2 3 4 5 6 7 8 9)

I can help you figure out what's wrong with those keys, but you will have to guide me.

I no longer have windows on the laptop, but can install a VM if need be.
Thank you for the tool, very well made :)

[Mostrapotski]

Nevermind, there is no numpad on GS65 ...
So i tried again with ge63 and and it's working just fine.
Thank you for your work.

[Askannz]

That's useful information, it means I can link the GS75 to the same keymap as the GE63. Thanks for your input !