Update $parsers NgModelController doc

[gillius]

Make it clear that the result of the $parsers pipeline is what goes to the model value. It was not clear to me for some time.

[IgorMinar]

I'm sorry, but I wasn't able to verify your CLA signature. CLA signature is required for any code contributions to AngularJS.

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[gillius]

OK, I have signed the CLA as Jason Winnebeck [email protected].

[IgorMinar]

CLA signature verified! Thank you!

Someone from the team will now triage your PR and it will be processed based on the determined priority (doc updates and fixes with tests are prioritized over other changes).

[pkozlowski-opensource]

Thnx @gillius !