Show non-$/ var use in actions in example

- Already mentioned in the adjacent prose
- Also include example that shows you don't have to use `$/.make` and can just make

Author: zoffixznet

doc/Language/grammars.pod6

@@ -340,9 +340,15 @@ grammar KeyValuePairs {
 }
 
 class KeyValuePairsActions {
-    method identifier($/) { $/.make: ~$/                          }
     method pair      ($/) { $/.make: $<key>.made => $<value>.made }
-    method TOP       ($/) { $/.make: $<pair>».made                }
+    method identifier($/) {
+        # subroutine `make` is the same as calling .make on $/
+        make ~$/
+    }
+    method TOP ($match) {
+        # can use any variable name for parameter, not just $/
+        $match.make: $match<pair>».made
+    }
 }
 
 my  $res = KeyValuePairs.parse(q:to/EOI/, :actions(KeyValuePairsActions)).made;