1. Get version number from Desktop\Fabulously Optimized-x.x.x.zip (aka CF file, I think that logic is already there in some python script I have)
2. Update version number on the file (github repo path)\MultiMC\Fabulously Optimized x.y.z\instance.cfg
3. Copy that file to Desktop\Fabulously Optimized x.x.x.zip\Fabulously Optimized x.x.x\instance.cfg

Ideally that action should be in the file MultiMC to Git.py instead of the current copy action in line 19.
The file paths should be variables similar to the ones I already have in scripts.

PRs are welcome.

Get version from what exactly? Filename or manifest inside?

Get version from the curseforge zip filename. Actually I guess there are multiple ways to get the name from, such as the multimc zip itself.

Why not curseforge manifest?

Yes, the manifest could be used for that, I'm not sure if it would just be any easier to do that.

x.x.x is just a placeholder or actual part of filename?

Placeholder of the version.

In 2, you mean update name var?