Add Instructions for Installing via Creator Companion CLI

[gentlecolts]

As stated in title. The creator companion GUI only supports windows, however the VRC SDK, and Unity, support Linux and Mac, current instructions are incomplete and lack guidance for non-windows users

[Spokeek]

I mean, that would require every project to add CLI explanations on their docs. Isn't all the explanations needed on VRChat docs ?

Or maybe i didn't get what you meant.

[gentlecolts]

It's generally common practice for package-managed software to include installation in the readme, it's not a big ask, installation is a one-liner, the important part is explicit statement of the package name. If i'm not mistaken, in this case that's vpm add package vrchat.blackstartx.gesture-manager

[Spokeek]

From what i tried on my side, that indeed seem to be the right command to add.

I'm letting the owner do so if needed.