Added docs for List.Capture. gfldex++, perlpilot++, ab6tract++

doc/Type/List.pod6

@@ -500,6 +500,41 @@ Usage:
 
 Returns the number of elements in the list (same as C<.elems>).
 
+=head2 method Capture
+
+Defined as:
+
+    method Capture() returns Capture:D
+
+Usage:
+
+    LIST.Capture
+
+Returns a L<Capture|/type/Capture> where each L<Pair|/type/Pair>, if any, in
+the C<List> has been converted to a named argument. All other elements in the
+C<List> are converted to positional arguments in the order they are found,
+i.e. the first non pair item in the list becomes the first positional argument,
+which gets index C<0>, the second non pair item becomes the second positional
+argument, getting index C<1> etc.
+
+    my $list = (7, 5, a => 2, b => 17);
+    my $capture = $list.Capture;
+    say $capture.keys;                                # (0 1 a b)
+    my-sub(|$capture);                                # 7, 5, 2, 17
+
+    sub my-sub($first, $second, :$a, :$b) {
+        say "$first, $second, $a, $b"
+    }
+
+A more advanced example demonstrating the returned C<Capture> being matched
+against a L<Signature|type/Signature>.
+
+    my $list = (7, 5, a => 2, b => 17);
+    say so $list.Capture ~~ :($ where * == 7,$,:$a,:$b); # True
+
+    $list = (8, 5, a => 2, b => 17);
+    say so $list.Capture ~~ :($ where * == 7,$,:$a,:$b); # False
+
 =head2 routine pick
 
 Defined as: