Reference documentation for `abs` and `add`
Merge branch 'develop' into reference
Added reference docs for abs, add, divide, multiply, subtract
Fixed broken links
Updated examples
Added reference docs for ceil, fix, floor, and round
Added reference docs for cube, exp, pow, square
Created a simple docgenerator to generate references. It's too boring to do manually
Some fixes in the docgenerator
yihaa, the first automatically generated reference docs for functions
Updated index and getting started
Merge branch 'develop' into reference

Conflicts:
	gulpfile.js
	lib/function/arithmetic/round.js
	package.json
Merge branch 'develop' into reference

Conflicts:
	lib/function/arithmetic/exp.js
Merge branch 'develop' into reference
Described how to generate documentation in `how_to_publish.md`
Docgenerator now supports descriptions with multiple paragraphs.
Added more reference docs (not all docs are complete yet)
Updated version number to 0.21.2-SNAPSHOT
Merge branch 'develop' into reference
Updated roadmap