docs(cookbook): remove the cookbook docs

The cookbook docs are now superceded by the guide. They are no longer available
in any menus and the only way to find them is to search for them. Remove!

Closes #5967
test(docs): convert example end to end doc tests from scenario runner to protractor

Thanks to jeffbcross, petebacondarwin, btford, jdeboer, tbosch for contributions!

Closes #6023
docs(compile/nodomevents): fix typo ng-mode -> ng-model

correcting directive name to ng-model instead of ng-mode in nodomevents.ngdoc

Correcting use of ng-model directive

Closes #6036
docs($provide): return instance of Ping, rather than constructor

Updating $provide.service method docs

The previous example provided for the service method did not work.  I've updated the example to a working example.

I think this version of the example will probably make more sense to most people, and the factory method would be
a better place for this sort of example.

Closes #6008