Merge pull request #249 from marip8/update/intro_to_urdf_doc

Update Intro-to-URDF documentation

gh_pages/_source/session3/Intro-to-URDF.md

@@ -88,7 +88,7 @@ Your goal is to describe a workcell that features:
    1. It helps to visualize your URDF as you add links, to verify things look as expected:
 
       ```
-      roslaunch urdf_tutorial display.launch model:=<RELATIVE_PATH_TO_URDF>
+      roslaunch urdf_tutorial display.launch model:=`rospack find myworkcell_support`/urdf/workcell.urdf
       ```
 
   _If nothing shows up in Rviz, you may need to change the base frame in RVIZ (left panel at top) to the name of one of the links in your model._