remove wrong invocant parameter to Grammar's parse methods

they are not only confusing to beginners, but also wrong
(as in: i use parse with a Grammar type object all the time)

Author: timo

lib/Language/grammars.pod

@@ -110,7 +110,7 @@ be used in conjunction with the grammar.
 
 =head3 method parse
 
-    method parse(Grammar:D: $str, :$rule = 'TOP', :$actions) returns Match:D
+    method parse($str, :$rule = 'TOP', :$actions) returns Match:D
 
 Matches the grammar against C<$str>, using C<$rule> as the starting rule,
 optionally applying C<$actions> as actions object.
@@ -153,7 +153,7 @@ This outputs:
 
 =head3 method subparse
 
-    method subparse(Grammar:D: $str, :$rule = 'TOP', :$actions) returns Match:D
+    method subparse($str, :$rule = 'TOP', :$actions) returns Match:D
 
 Matches the grammar against C<$str>, using C<$rule> as the starting rule,
 optionally applying C<$actions> as actions object.
@@ -163,7 +163,7 @@ of the supplied string.
 
 =head3 method parsefile
 
-    method parsefile(Grammar:D: Cool $filename as Str, *%opts) returns Match:D
+    method parsefile(Cool $filename as Str, *%opts) returns Match:D
 
 Parses the contents of the file C<$filename> with the L<parse> method,
 passing along any named options in C<%opts>.