Fixes unimatch example.

Closes #3509. Also grammar fixes, and added explanation.

Author: JJ

doc/Type/Cool.pod6

@@ -1070,14 +1070,17 @@ Defined as:
     multi sub unimatch(Str:D $str, |c)
     multi unimatch(Int:D $code, Stringy:D $pvalname, Stringy:D $propname = $pvalname)
 
-Checks if the given integer codepoint or the first letter of the string given
-have a unicode property equal to the value you give. If you supply the Unicode
+Checks if the given integer codepoint or the first letter of the given string
+has a unicode property equal to the value you give. If you supply the Unicode
 property to be checked it will only return True if that property matches the
 given value.
 
     say unimatch 'A', 'Latin';           # OUTPUT: «True␤»
     say unimatch 'A', 'Latin', 'Script'; # OUTPUT: «True␤»
-    say unimatch 'A', 'Ll';              # OUTPUT: «True␤»
+    say unimatch 'A', 'Ll';              # OUTPUT: «False␤»
+
+The last property corresponds to "lowercase letter", which explains why it
+returns false.
 
 =head2 routine chop