Item renaming

[pyrohedgehog]

Removed some unneeded array constructors in calls. It makes little difference but clears things up a bit. renamed one-letter variables to something clearer.

this shouldn't have any real changing effects. PR is purely cleaning and renaming.

[itsubaki]

Thanks for PR.

The variable g in the quantum/gate package should be immediately recognizable as representing gate in many cases. The Array constructors are certainly not needed. I will merge them if you can create a PR for this part.

[itsubaki]

https://github.com/itsubaki/q/pull/26