README fix: markdown -> rst

Author: mfisher87

README.rst

@@ -53,12 +53,10 @@ resulting visualizations and use the editor tool `on this website
 Reproducing viridis
 ^^^^^^^^^^^^^^^^^^^
 
-Load [viridis AKA option_d.py](https://github.com/BIDS/colormap/) using:
+Load `viridis AKA option_d.py <https://github.com/BIDS/colormap/>`__ using::
 
-```
-python -m viscm --uniform-space buggy-CAM02-UCS -m Bezier edit /tmp/option_d.py
-```
+  viscm --uniform-space buggy-CAM02-UCS -m Bezier edit /tmp/option_d.py
 
 Note that there was a small bug in the assumed sRGB viewing conditions
 while designing viridis. It does not affect the outcome by much. Also
-see `python -m viscm --help`.
+see :code:`viscm --help`.