Added an example and some details. Closes #2828

Author: JJ

doc/Type/IO/Notification.pod6

@@ -11,8 +11,7 @@ enum FileChangeEvent (:FileChanged(1), :FileRenamed(2));
 =for code :skip-test<compile time error>
 class IO::Notification {}
 
-
-Essentially, this class exists for the C<IO::Notification.watch-path($path)>
+Essentially, this class exists as a placeholder for the C<IO::Notification.watch-path($path)>
 method, that produces a L<Supply|/type/Supply>
 of L<C<IO::Notification::Change>|/type/IO::Notification::Change> events for a
 file or directory.
@@ -31,7 +30,35 @@ C<$path> is a directory, both modifications to the directory itself (for
 example permission changes) and to files in the directory (including new
 files in the directory) are reported.
 
-C<:$scheduler> allows you to specify which thread scheduler is
-responsible for the notification stream.
+The C<:$scheduler> named argument allows you to specify which thread scheduler
+is going to be responsible for the notification stream; it can be omitted if
+the default scheduler is used.
+
+=begin code
+my $supply = IO::Notification.watch-path( "/var/log/syslog" );
+
+$supply.tap( -> $v { say "Got ", $v });
+
+sleep 60;
+=end code
+
+This snippet of code sets a watch on the system log file, emitting the kind
+of event that has occurred or capturing an error otherwise; the created
+C<Supply> is tapped, and the event printed. It does so for 60 minutes,
+emitting something like this:
+
+=for code
+Got /var/log/syslog: FileChanged
+Got /var/log/syslog: FileChanged
+Got /var/log/syslog: FileChanged
+Got /var/log/syslog: FileChanged
+Got /var/log/syslog: FileChanged
+Got /var/log/syslog: FileChanged
+Got /var/log/syslog: FileChanged
+Got /var/log/syslog: FileChanged
+
+The only kind of information this method provides is the bare fact that
+something has change or been renamed. You will need to actually open and read
+the file or directory to check the actual changes.
 
 =end pod