Fix locations of expect param in docs

`expect` can be placed before `rule` not in `rule`.

Author: yui-knk

doc/en/grammar.en.rdoc

@@ -131,8 +131,8 @@ Racc supports Bison's "expect" directive to declare the expected
 number of shift/reduce conflicts.
 --
 class MyParser
-rule
   expect 3
+rule
     :
     :
 --

doc/en/grammar2.en.rdoc

@@ -127,8 +127,8 @@ Racc has bison's "expect" directive.
   # Example
 
   class MyParser
-  rule
     expect 3
+  rule
       :
       :