Grammar cop polices grammar 🚓

A verb was missing in this sentence. "be located" seems to fit.

Author: theinterned

README.md

@@ -86,7 +86,7 @@ The following restrictions are placed on the `:export` syntax:
 The following are desirable for output readability, but not enforced:
 
 - There should be only one `:export` block
-- It should at the top of the file, but after any `:import` blocks
+- It should be located at the top of the file, but after any `:import` blocks
 
 ### :import