Define PathMatchers and convert base_paths to a list of PathMatchers.
Extend ActionDispatch::Routing::Mapper so get and root methods will populate RenderStatic::Middleware.base_paths

If get or root are given the option :crawlable, they add a PathMatcher to base_paths.
The root method adds a exact matcher for the root path.
The get method adds a start_with matcher and also sets anchor: false for the route unless already set.