Update CONTRIBUTING.md

Language corrections (as well as spelling Linnovate right!). I would very much prefer you include a copyright assignment clause. Here you are only licensing the contribution. Some communitied do not like copyright assignment, but I personnaly, for this piece of code find it simpler.  At least for larger contributions and contributions made by companies. See http://dreamsongs.com/ihe/IHE-110.html for an example clause..
more prototypal
Merge pull request #34 from andrija-hers/modulecleanup

Looking good, +1'ed from @fyockm as well - merging.
bumping version
Fixing typo in prototype.aggregateAsset

Typo keeps prevents assets being aggregated.
Merge pull request #35 from tkh44/patch-1

Fixing typo in prototype.aggregateAsset
bumping version to 21
splitting the core
added preinstall script for mean.json
added preinstall script for mean.json
preinstall as a separate command
mena.json to work with versions
crypto reference fix
Merge branch 'andrija-hers-master'
Merge pull request #36 from andrija-hers/master

This PR sorted out a lot of style and structure issue in mean.js. Many thanks to @andrija-hers
Merge branch 'master' of github.com:linnovate/mean-cli
merge contrib from meanio repo
Merge mean-cli
better error messages for init and register
fix jshint errors