Update doc/rakefile.rdoc

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: hsbt

doc/rakefile.rdoc

@@ -369,8 +369,9 @@ automatically creates an implicit file task for it. For example:
   $ touch hello_world      # Create a file with the same name
   $ rake hello_world       # Now succeeds automatically
 
-Use the <tt>--rules</tt> command line option to trace how tasks are
-being resolved.
+Use the <tt>--rules</tt> command line option to trace how rules are
+resolved when searching for tasks; note that creation of implicit file
+tasks is not traced.
 
 == Importing Dependencies