Starting MapReduce docs
Singularize object under Inserting data
Adding more examples for MapReduce
Adding missing code in map reduce section
Fixing a couple problems in the examples
A Controller shouldn't contain business logic

Also slightly changed phrasing so that the word post now is plural and can't be confused to post meaning "after"
Merge pull request #972 from spiliot/patch-7

A Controller shouldn't contain business logic
Merge pull request #970 from bcrowe/hotfix-objectSingular

Singularize object under Inserting data
Add skeleton for collection docs.
Add some docs for ResultSets.

Provide a simple and interesting example, linking to the collection docs
for the real meat.
Better wording.
Start Model section in migration guide.
Start collection docs.
Fixed problems found in review
More docs for map-reduce
Showing how to remove all mapReduce methods
Fixed small typo
Fixing typos
Reversing arguments for mapReduce callbacks
Merge branch '3.0' of github.com:cakephp/docs into 3.0