renamed a few occurances of "web page" to "renderer"
renamed a few files that had "browser" in their name to "main-process"
note that there are still many occurances of web page.
If you name your app's folder `app/` and if you run the atom-shell from the directory above that, it will result in an error, which I believe is caused by resolving `require('app')` to your `app/` folder.
So just to avoid confusion where someone might create an app with that folder and run the atom-shell from that directory.
I wrote up some details getting atom-shell working using the grunt plugin.
- https://github.com/atom/atom-shell/issues/256#issuecomment-42464026
