docs: clarify $USER in HPCDME properties

docs/HPCDME/setup.md

@@ -33,6 +33,8 @@ cp hpcdme.properties-sample hpcdme.properties
 
 Some of the parameters in this file have become obsolete over the course of time and are commmented out. Change paths and default values, as needed
 
+> Note: replace `$USER` with your actual username in the properties file. Bash variables will not be interpolated.
+
 ```bash
 #HPC DME Server URL
 #Production server settings
@@ -152,4 +154,4 @@ Done! You are now all set to use CLUs.
   *  [HPC_DME_APIs repo](https://github.com/CBIIT/HPC_DME_APIs/)
   *  [User guides](https://github.com/CBIIT/HPC_DME_APIs/tree/master/doc/guides)
   *  [Wiki pages](https://wiki.nci.nih.gov/display/DMEdoc/Getting+Started+with+DME+CLU)
-  *  [Yuri Dinh](mailto:[email protected])
+  *  [Yuri Dinh](mailto:[email protected])