Update docs for relative path fixes in Supervisor#369

docs/configuration.rst

@@ -561,9 +561,9 @@ where specified.
 
   The command that will be run when this program is started.  The
   command can be either absolute (e.g. ``/path/to/programname``) or
-  relative (e.g. ``programname``).  If it is relative, the
-  supervisord's environment ``$PATH`` will be searched for the
-  executable.  Programs can accept arguments, e.g. ``/path/to/program
+  relative (e.g. ``programname``).  If it is relative, the program's
+  directory and supervisord’s environment $PATH will be searched for
+  the executable.  Programs can accept arguments, e.g. ``/path/to/program
   foo bar``.  The command line can use double quotes to group
   arguments with spaces in them to pass to the program,
   e.g. ``/path/to/program/name -p "foo bar"``.  Note that the value of