Add clarification for :pos/:continue

hobbified++ # https://www.reddit.com/r/perl6/comments/5bx66y/matching_adverbs_difference_between_p2_and_c2/d9s589q/

doc/Language/regexes.pod6

@@ -1111,6 +1111,12 @@ case it defaults to C<$/.to>.
         say ~m:c(2)/a./;    # a2
     }
 
+I<Note:> unlike C<:pos>, a match with :continue() will attempt, to
+match further in the string, instead of failing:
+
+    say "abcdefg" ~~ m:c(3)/e.+/; # OUTPUT«｢efg｣␤»
+    say "abcdefg" ~~ m:p(3)/e.+/; # OUTPUT«False␤»
+
 =head3 Exhaustive
 
 To find all possible matches of a regex – including overlapping ones – and
@@ -1165,6 +1171,12 @@ Anchor the match at a specific position in the string:
 
 C<:p> is shorthand for C<:pos>.
 
+I<Note:> unlike C<:continue>, a match anchored with :pos() will fail,
+instead of attempting to match further down the string:
+
+    say "abcdefg" ~~ m:c(3)/e.+/; # OUTPUT«｢efg｣␤»
+    say "abcdefg" ~~ m:p(3)/e.+/; # OUTPUT«False␤»
+
 =head3 Overlap
 
 To get several matches, including overlapping matches, but only one (the