added a subsection about color maps, which shows built-in color maps
and how to use them
added a subsection on the Color-Map Specification Language (CMSL),
with a simple grammar specification, a detailed explanation of its
workings and a few examples along visualizations
added a subsection on changing palettes
added compile-time visualizations of heatmaps using
sphinxcontrib.datatemplates
added sphinx.datatemplates requirement
added config option generated_path to choose where generated images
should be stored
generated_path
to choose where generated images should be stored