Eliminates sym index duplicate, #1912

Author: tisonkun

doc/Language/grammars.pod6

@@ -81,7 +81,7 @@ into effect for the Regex:
     say so 'once upon a time' ~~ &space-y;     # OUTPUT: «True␤»
     =end code
 
-=head1 X<Creating Grammars>
+=head1 X<Creating Grammars|declarator, grammar>
 =SUBTITLE Group of named regexes that form a formal grammar
 
 L<Grammar|/type/Grammar> is the superclass that classes automatically get when
@@ -92,7 +92,7 @@ L<action object|/language/grammars#Action_Objects> is recommended to be used in
 conjunction with the grammar.
 
 
-=head2 X«Proto regexes| sym; :sym<>; proto regex;declarator,grammar»
+=head2 X«Proto regexes| :sym<>; proto regex»
 
 L<Grammar|/type/Grammar>s are composed of rules, tokens and regexes;
 they are actually methods, since grammars are classes. These methods
@@ -235,7 +235,7 @@ You can also redefine the default C<ws> token:
     }.parse: "4   \n\n 5"; # Fails
 
 
-=head3 X<C<sym>|sym>
+=head3 X«C<sym>|<sym>»
 
 The C«<sym>» token can be used inside proto regexes to match the string value of the C<:sym>
 adverb for that particular regex: