fix extension

source/thermal.rst

@@ -3,7 +3,7 @@ Thermal Support
 
 ODM has support for radiometric calibration of thermal data, which is able to generate temperature orthophotos from long-wave infrared (LWIR) cameras. LWIR images can be processed alone or as part of a multispectral dataset.
 
-.. figure:: images/thermal.jpg
+.. figure:: images/thermal.jpeg
    :alt: Screen shot of thermal imagery as displayed in WebODM
    :align: center