Added some documentation to request.py, removed extra line in blueprints.py, and minor grammar enhancements to blueprints.md and middleware.md

sanic/blueprints.py

@@ -76,7 +76,6 @@ class Blueprint:
     def middleware(self, *args, **kwargs):
         """
         """
-
         def register_middleware(middleware):
             self.record(lambda s: s.add_middleware(middleware, *args, **kwargs))
             return middleware

sanic/request.py

@@ -26,6 +26,9 @@ class RequestParameters(dict):
 
 
 class Request:
+    """
+    Properties of an HTTP request such as URL, headers, etc.
+    """
     __slots__ = (
         'url', 'headers', 'version', 'method',
         'query_string', 'body',