Change start_url to index.html to work locally as well (#403)
Change start_url to index.html to work locally as well (#403)

* Change start_url to index.html to work locally as well

* index.html -> /index.html

ampproject/amp-by-example,ampproject/amp-by-example,camelburrito/amp-by-example,ampproject/amp-by-example,ampproject/amp-by-example,camelburrito/amp-by-example,camelburrito/amp-by-example,camelburrito/amp-by-example