README.org
images (centered)
#+html: <p align="center"><img src="images/wim-128.png" /></p>
two images side-by-side
#+html: <div><p align="center"><img src="img/rate_map.png" width="50%"/><img src="img/path_map.png" width="50%"/></p></div>
line breaks (add vertical space)
\\
inserts a line break