mdn: update HTTP

lib/docs/filters/http/entries.rb

@@ -84,6 +84,11 @@ module Docs
           [3, 4],
           []
         ],
+        'rfc7540' => [
+          (3..11).to_a,
+          [],
+          []
+        ],
         'rfc5023' => [
           [],
           [],

lib/docs/scrapers/http.rb

@@ -37,6 +37,7 @@ module Docs
          https://tools.ietf.org/html/rfc7233
          https://tools.ietf.org/html/rfc7234
          https://tools.ietf.org/html/rfc7235
+         https://tools.ietf.org/html/rfc7540
          https://tools.ietf.org/html/rfc5023)
     end
   end