Fixes assignment and iteration issues arising from the use of $dirs

Now changed to @Dirs and a proper list assignment, which is more accessible to beginners.

Author: Xliff

doc/Language/enumeration.pod6

@@ -38,11 +38,12 @@ sub check-dir-status($dir --> DirStat) {
 }
 
 # test each of three directories by a non-root user
-my $dirs =
+my @dirs = (
     '/tmp',  # normally writable by any user
     '/',     # writable only by root
-    '~/tmp'; # a non-existent dir in the user's home dir
-for $dirs -> $dir {
+    '~/tmp'  # a non-existent dir in the user's home dir
+);
+for @dirs -> $dir {
     my $stat = check-dir-status $dir;
     say "status of dir '$dir': $stat";
     if $stat ~~ CanWrite {