Minor generalization of new instructions

Signed-off-by: Jonathan Stone <jstone@lucasfilm.com>

javascript/build_javascript_win.bat

@@ -1,9 +1,8 @@
-@rem This script builds the MaterialX system on Windows. The final command starts a local server so that you can then 
-@rem run the interactive viewer locally. Here is a typical line to paste into your browser at that point (withouth the @rem):
-@rem   http://localhost:8080/index.html?file=Materials/Examples/UsdPreviewSurface/usd_preview_surface_default.mtlx
+@rem This script builds MaterialX JavaScript on Windows. The final command starts a local server, allowing you to
+@rem run the MaterialX Web Viewer locally by entering 'http://localhost:8080' in the search bar of your browser.
 @echo --------------------- Setup Emscripten ---------------------
 @echo on
-@rem You will likely need to change these paths to wherever you store your Github repositories
+@rem Edit the following paths to match your local locations for the Emscripten and MaterialX projects.
 set EMSDK_LOCATION=C:/GitHub/emsdk
 set MATERIALX_LOCATION=C:/GitHub/MaterialX
 call %EMSDK_LOCATION%/emsdk.bat install latest