Improved docstring for create_lib_order_files().

tools/oneclick/base/hdl_config.py

@@ -177,9 +177,10 @@ class HdlConfig:
         return cm.unlistify(build_dirs)
 
     def create_lib_order_files(self, lib_names=None):
-        """Create the compile order file for all HDL libraries in the specified list of lib_names.
+        """Create the compile order file '<lib_name>_lib_order.txt' for all HDL libraries in the specified list of lib_names.
         
            The file is stored in the sim build directory of the HDL library.
+           The file is read by commands.do in Modelsim to avoid having to derive the library compile order in TCL.
         """
         if lib_names==None: lib_names=self.lib_names
         lib_dicts = self.libs.get_dicts('hdl_lib_name', lib_names)