Add native-dom mode documentation

[ro0gr]

I guess we're gonna to release native-dom mode in 1.13 so I've copy-pasted pages from v1.12.x to v1.13.x.

Also a simple page describing why do we need ember-native-dom-helpers and how to enable it was added.

I'm open for any suggestions on re-phrasing or any improvements of the new page cause I'm not very good in gluing the words 😄

topics to cover:

• wait for Add native-events mode #339 to be merged to stabilize API
• explain ember-native-dom-event-dispatcher
• jquery
  • ember@2.13.0-beta.2
  • events
  • isVisible Use project's jquery if available #346

[ro0gr]

tbh I haven't ruby installed locally 🙊 ... so I haven't tested it yet.
I'm curious if there is a way to test resulting docs instantly?

[magistrula]

Suggest Triggering Native vs. jQuery DOM Events as the title of this page. Would be nice to have something as expressive as possible so that people can easily realize "oh, yeah...that sounds like what I'm dealing with."

[ro0gr]

Seems like it's a good direction. I'm finally agreed with you that the key thing here are Events

[ro0gr]

from slack by @magistrula

in jquery event mode isVisible returns false for an empty div, but in native event mode, isVisible returns true for an empty div.

[magistrula]

@ro0gr I'm going to close this PR, since these documentation updates were handled in this week's release. Thanks for supplying the initial draft of the documentation for native-events mode!