Contribution section added to README.md
reference CONTRIBUTING.md
Merge pull request #3292 from ysksn/master

Contribution section added to README.md
fixed duplicated @param
Merge pull request #3298 from makepanic/patch-1

fixed duplicated @param
update ember-source
Fix typo in docstring
Reuse variable
fixup docs (mostly formatting)

(@stefanpenner / @rjackson)
Merge pull request #3304 from sebastianseilund/simplification1

Reuse variable
Merge pull request #3302 from alexspeller/typo

Fix typo in docstring
Merge pull request #3305 from stefanpenner/improve_docs

improve docs (formatting mostly)
Merge pull request #3300 from stefanpenner/ember-source-bump

update ember-source