Adds an example

And clarifies what happens if the second argument is not present. Addresses #2303. Not closing it until everyone is happy.

Author: JJ

doc/Type/Cool.pod6

@@ -1203,19 +1203,25 @@ L<Regex|/type/Regex> as a list of strings.
 
     multi method contains(Cool:D: Str(Cool) $needle, Cool $start? --> Bool:D)
 
-Coerces the invocant and first argument to L<Str|/type/Str>, and searches for
-C<$needle> in the string starting from C<$start> characters into the string. Returns C<True> if C<$needle>
-is found.
+Coerces the invocant and first argument to L<C<Str>|/type/Str>, and
+searches for C<$needle> in the string starting from C<$start> characters
+into the string. Returns C<True> if C<$needle> is found. C<$start> is an
+optional parameter, and if it's not present, C<contains> will search
+from the beginning of the string.
 
     say "Hello, World".contains('Hello');      # OUTPUT: «True␤»
     say "Hello, World".contains('hello');      # OUTPUT: «False␤»
+    say "Hello, World".contains('Hello', 1);   # OUTPUT: «False␤»
     say "Hello, World".contains(',');          # OUTPUT: «True␤»
     say "Hello, World".contains(',', 3);       # OUTPUT: «True␤»
     say "Hello, World".contains(',', 10);      # OUTPUT: «False␤»
 
-Note that because of how a L<List|/type/List> or L<Array|/type/Array> is
-L<coerced|/type/List#method_Str> into a L<Str|/type/Str>, the results may
-sometimes be surprising. See L<traps|/language/traps#Lists_become_strings,_so_beware_.contains()>.
+In the third case, the C<'Hello'> string is not found since we have
+started looking at the second position in it (index 1). Note that
+because of how a L<List|/type/List> or L<Array|/type/Array> is
+L<coerced|/type/List#method_Str> into a L<Str|/type/Str>, the results
+may sometimes be surprising. See
+L<traps|/language/traps#Lists_become_strings,_so_beware_.contains()>.
 
 =head2 routine index
 
@@ -1411,14 +1417,15 @@ Returns a C<Complex> with the coordinates corresponding to the angle in
 radians and magnitude corresponding to the object value or C<$mag> in
 the case it's being used as a C<sub>
 
-    say 1.unpolar(⅓*pi);# OUTPUT:                «0.5000000000000001+0.8660254037844386i␤»
+    say 1.unpolar(⅓*pi);
+    # OUTPUT: «0.5000000000000001+0.8660254037844386i␤»
 
 =begin comment
 
 
 
 TODO:
-unpolar, fmt, substr-rw, trans,
+fmt, substr-rw, trans,
 match, subst, sprintf, printf, samecase
 
 =end comment