Add support for anchor urls

[zendevil]

When I add an anchor into the url like so: "http://myurl.com/foo/#bar1" or "http://myurl.com/foo/#bar2", pushy is unable to detect these. How can I make this work in pushy?

[rafaeldelboni]

I had a similar problem and I needed to set the to solve path-prefix
Here is my "fork", if the owners like I can make a PR with this, they aren't breaking changes.

[olivergeorge]

Just to reiterate the value this would bring.

While normal URLs are nice for lots of reasons it's additional friction if you're deploying a simple webapp as static files.

The complication being the webserver needs to be configured to redirect multiple URLs to a single index.html page. That's beyond the scope of a simple CDN deploy.

Azure App Service has some configuration which does it neatly. AWS S3 barely does (using generic error code response). It's all a bit messy.