Simplifying the observable "get" example

The "get" example referenced a method on "this" called "getEach",
which is not a method of Ember.Object.

Furthermore the signature used with "getEach" in the example does not
exist in the framework.  This can be confusing to new users.
Fix typo in route.js

![no newline](http://f.cl.ly/items/2C1C2V321H352Q2I2E2c/route_js_sans_newline.png)
Merge pull request #3616 from zeppelin/patch-2

Fix typo in route.js
Merge pull request #3615 from corsen2000/computed-get-doc-fix

Simplifying / correcting the observable "get" example