changed to figure

docs/index.rst

@@ -3,14 +3,11 @@ MantidImaging
 
 Mantid Imaging is a graphical toolkit for performing 3D reconstruction of neutron tomography data. It provides an easy-to-use graphical interface to a wide range of pre/post-processing operations, tilt correction, and reconstruction algorithms, accommodating for tomography users with varying data complexity and image analysis background knowledge. It utilizes a flexible plugin system that allows easy integration of external software, and has allowed us to re-use software widely known in the neutron tomography community.
 
-.. image:: _static/main_window.png
+.. figure:: _static/main_window.png
    :alt: Main Window
    :align: center
    :width: 100%
 
-.. raw:: html
-
-    <div style="margin-bottom: 20px;"></div>
 
 .. grid:: 1 1 2 2
     :gutter: 4