Switch .innerText DOM output to .textContent

.innerText started as an IE-ism, but .textContent is the WC3 standard. Eventually, IE9+ supported textContent, but Firefox stood firm (or "stubborn") on NOT supporting innerText. As stands, innerText will break this example for modern Firefox browsers, and I don't believe that punishing IE8 users is necessarily a bad thing. ;)

Mind, there's ways to normalize use of this property for maximum browser compat, but I believe the spirit of this example is to keep the code as lean as possible.
Merge pull request #76 from Markleford/patch-1

Switch .innerText DOM output to .textContent