0.12.0 release

[lachlanmcdonald]

• [x] Document cellular2D
• [x] Document cellular3D
• [x] Document gradient
• [x] Document treemap
• [x] Document truchet
• [x] Update grass shader docs
• [x] Update shader specs for each shader replacing 0-1 with 0-100
• [x] Re-generate commands documentation

Other changes

• clamp removed from a number of shaders to fix bugs with some hardware. clamp is still used within the truchet, cellular2D, and cellular3D shaders.
• Fixed an issue where diagonal wouldn't work on certain hardware due to an overloaded mod function
• All shaders which accepted a value from 0-1 now accept 0-100 to make it easier to adjust in the UI.
• Changes to the range of the Growth value on the grass shader