Updated findrx docs (#5263)

* Updated findrx docs

* Addressed PR feedback

isis/src/base/apps/findrx/findrx.xml

@@ -10,6 +10,9 @@
     It will also modify the cube's label so the Reseaus are matched with sub-pixel accuracy.
     The new reseau coordinate set is then set to "Refined", and the validity of the pixels that
     have nothing wrong will be set to 1. 
+    NOTE: Please be aware that refining the reseaux locations will modify the image distortion 
+    once applications that utilize the camera model (campt, qview, etc) are used. Thus findrx has 
+    the practical effect of changing the geometry of the image.
   </description>
 
   <category>