v4.1.1

• fix for issue #411 which allows for overlapping regexp
  route to the correct handler through a recursive tree search, thanks to @Jahaja for the PR/fix!
• new middleware.RouteHeaders as a simple router for request headers with wildcard support
• updated the FileServer example to a much better implementation, see https://github.com/go-chi/chi/blob/master/_examples/fileserver/main.go
• History of changes: see v4.1.0...v4.1.1