don't add trailing slash in sprintf

README.md

@@ -52,7 +52,7 @@ val my_fancy_route : unit -> (int -> 'a, 'a) Routes.path = <fun>
 val print_route : int -> string = <fun>
 
 # print_route 12;;
-- : string = "user/12/add/"
+- : string = "user/12/add"
 ```
 
 ## Installation

src/routes.ml

@@ -150,13 +150,13 @@ let rec route_pattern : type a b. (a, b) path -> PatternTrie.Key.t list = functi
   | Match (w, fmt) -> PatternTrie.Key.Match w :: route_pattern fmt
   | Conv (_, fmt) -> PatternTrie.Key.Capture :: route_pattern fmt
 
-let rec ksprintf : type a b. (string -> b) -> (a, b) path -> a =
+let rec ksprintf : type a b. (string list -> b) -> (a, b) path -> a =
  fun k -> function
-  | End -> k ""
-  | Match (w, fmt) -> ksprintf (fun s -> k @@ w ^ "/" ^ s) fmt
-  | Conv ({ to_; _ }, fmt) -> fun x -> ksprintf (fun rest -> k @@ to_ x ^ "/" ^ rest) fmt
+  | End -> k []
+  | Match (w, fmt) -> ksprintf (fun s -> k @@ (w :: s)) fmt
+  | Conv ({ to_; _ }, fmt) -> fun x -> ksprintf (fun rest -> k @@ (to_ x :: rest)) fmt
 
-let sprintf r = ksprintf (fun x -> x) (r ())
+let sprintf r = ksprintf (fun x -> String.concat "/" x) (r ())
 
 let parse_route fmt handler params =
   let rec match_target : type a b. (a, b) path -> a -> string list -> b option =