Add unit type to rotation and skew methods

Something that allows you to specify the unit for rotation, such as rad or turn Rematrix.rotate(0.5, 'rad') perhaps?

— @davidkpiano

Units

• deg — Degrees. There are 360 degrees in a full circle.
• grad — Gradians, also known as “gons” or “grades”. There are 400 gradians in a full circle.
• rad — Radians. There are 2π radians in a full circle.
• turn — Turns. There is 1 turn in a full circle.

Source: https://drafts.csswg.org/css-values-3/#angles

Re: #1

[jlmakes]

I rather like the first suggestion, as it handles two arguments passed to skew nicely:

const { deg, turn } = Rematrix
Rematrix.skew(deg(45), turn(0.5))

[davidkpiano]

Another option: (not a breaking change, just add static methods to the rotate() function)

Rematrix.rotate.deg(180)
Rematrix.rotate.turn(.5)
Rematrix.rotate.grad(200)