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The cookbook docs are now superceded by the guide.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
chore(end2end): remove old references to the scenario runner and update to point to protractor