Rename `generate-swiftsyntax` to `generate-swift-syntax`

[ahoppen]

generate-swiftsyntax generates the entire swift-syntax package, not just the SwiftSyntax module. Thus, it should be named generate-swift-syntax.

[ahoppen]

Tracked in Apple’s issue tracker as rdar://112672032

[arirays]

Can I contribute to the project?

[Matejkob]

I was going through issues and encountered this one; I believe it was fixed #2073.

[ahoppen]

Oh, yes. Thanks for noticing.