Updates to History.md.
Updates to History.md.

* use code in one more place
* use the same case for HSL/HSLA
* link to /package.json

tomByrer/clean-css,shelsonjava/clean-css,GerHobbelt/clean-css,island205/clean-css,HossainKhademian/CleanCss,MartyIX/clean-css,vlajos/clean-css,webconnex/clean-css,scottgonzalez/clean-css,stuht/clean-css,yomed/clean-css,jakubpawlowicz/clean-css