fixes numerics links

And adds reference to 0d, which was not mentioned albeit indexed. Refs #2568

Author: JJ

doc/Language/numerics.pod6

@@ -677,7 +677,7 @@ say f $x;
 
 However, this rule is waived if a call is being made where one of the arguments
 is a native type and another one is a
-L<numeric literal|/syntax/Number literals>:
+L<numeric literal|/language/syntax#Number_literals>:
 
 =begin code
 multi f(int, int) {}

doc/Language/syntax.pod6

@@ -576,12 +576,12 @@ X<|0x (radix form)>
 X<|Number (literals)>
 =head3 Number literals
 
-Number literals are generally specified in base ten, unless a prefix
-like C<0x> (heB<x>adecimal, base 16), C<0o> (B<o>ctal, base 8) or C<0b>
-(B<b>inary, base 2) or an explicit base in adverbial notation like C<<
-:16<A0> >> specifies it otherwise. Unlike other programming languages,
-leading zeros do I<not> indicate base 8; instead a compile-time warning
-is issued.
+Number literals are generally specified in base ten (which can be used
+literally, if needed, via the prefix C<0d>), unless a prefix like C<0x>
+(heB<x>adecimal, base 16), C<0o> (B<o>ctal, base 8) or C<0b> (B<b>inary, base 2)
+or an explicit base in adverbial notation like C<< :16<A0> >> specifies it
+otherwise. Unlike other programming languages, leading zeros do I<not> indicate
+base 8; instead a compile-time warning is issued.
 
 In all literal formats, you can use underscores to group digits; they
 don't carry any semantic information; the following literals all