docs(guide/understanding_controller): correct grammar

Add the word "to" to improve grammar.

Closes #4698
docs(CONTRIBUTING.md): add more info for contributors

Closes #4636
docs(api): improve grammar

Closes #4690
docs(guide/e2e-testing): fix typo

Closes #4700
docs($route): change example module name

The name of the example module is `ngView`, which might cause needless confusion.
Changed name to `ngViewExample`, which should make it clearer.

Closes #4702