Narrow conditions for using Parse method

Closes #15

Narrow conditions for using Parse method

Closes #15

Fix git version environment problem

Handle regex {} quantifiers correctly

Eliminate need for VirtualUnaryTuple extraction node type

Documentation (#18)

* Better documentation

* More documentation updates

Add capture group cache for Range calculation

Upgrade to .NET 8.0 for build

VirtualUnaryTuple should reflect level N, not N+1

Fix ListOfList bug and another unit test