* Include Array.prototype.includes polyfill
In https://github.com/ianstormtaylor/slate/commit/070a700
the `default` feature set was added
and the `Array.prototype.includes` feature removed
from the polyfill.io request.
I think it's great to include the `default` feature set,
but, `Array.prototype.includes` is not included in the `default` set,
so we have to explicitly request it.
IE 11 needs an `Array.prototype.includes` polyfill
in order for the examples to work.
* Update dev.html
* Update index.html
* Updated examples/dev.html so that the script would reload on a page refresh
* Made watch:examples verbose so we know when watchify has finished its work.
