Parameter to tell swashbuckle not to register a route for index.html so ...

...mvc view can be used

I needed to be able to render index.html as a view, but this wasn't obviously possible as it was already going through the SwaggerUiHandler.
I added an overload to the Init method which allows you to tell swashbuckle not to register a route for index.html so that it can be registered in the containing MVC application instead.

This works quite nicely in my situation and helped solve some issues I was having with server paths varying on different environments. I think it also gives me more flexibility going forward as I am currently using an iframe to render the swagger page but I could now in theory do it via a PartialView (I think).