make suggestion

docs/faq.rst

@@ -414,11 +414,8 @@ How can I make a blank request?
     
     from scrapy import Request
 
-    def make_blank_request(your_call_back):
-        yield Request(
-            url="data:,",
-            callback=your_call_back,
-        )
+
+    blank_request = Request("data:,")
 
 In this case, the URL is set to a data URI scheme. Data URLs allow you to include data 
 in-line in web pages as if they were external resources. The "data:" scheme with an empty