Refactor and fix some docs

src/kemal/handler.cr

@@ -2,7 +2,7 @@ module Kemal
   # `Kemal::Handler` is a subclass of `HTTP::Handler`.
   #
   # It adds `only`, `only_match?`, `exclude`, `exclude_match?`.
-  # These methods are useful for custom handlers for conditional execution.
+  # These methods are useful for the conditional execution of custom handlers .
   class Handler
     include HTTP::Handler
     @@only_routes_tree = Radix::Tree(String).new

src/kemal/route_handler.cr

@@ -1,8 +1,6 @@
 require "radix"
 
 module Kemal
-  # Main handler which handles all the HTTP requests.
-  # Routing, parsing, rendering e.g are done in this handler.
   class RouteHandler
     include HTTP::Handler
     INSTANCE = new

src/kemal/websocket_handler.cr

@@ -1,6 +1,4 @@
 module Kemal
-  # Used for building a WebSocket route.
-  # For each WebSocket route a new handler is created and registered to global handlers.
   class WebSocketHandler
     include HTTP::Handler
     INSTANCE = new