update to use gif

source/using.rst

@@ -132,7 +132,9 @@ From James and Robson (2014), `CC BY 4.0 <https://creativecommons.org/licenses/b
 
 As this approach to flying can be take longer than typical flights, a pilot or team can fly a small area using the above approach. OpenDroneMap will generate a calibration file called cameras.json that then can be imported to be used to calibrate another flight that is more efficiently but, from a self calibration perspective, less accurately.
 
-.. figure:: images/flightplanning.gif
+.. only:: html
+
+  .. figure:: images/flightplanning.gif
     :alt: animation showing optimum
     :align: center