Pointing-options specification involves specifying list of instrument orientations (with respect to the NADIR_POINTING frame). The same can however be achieved by specifying the instrument orientations as separate 'modes'.
If this is done, it shall also require to do away with the orbitpy.coveragecalculator.PointingOptionsWithGridCoverage class and corresponding feature.
Similar behaviour as in ga4gh/vrs#345 when the sphinx_rtd_theme 1.0.0 is used. Currently installation is forced to use the 0.5.2 version. Need to find the fix to make it make with the latest version.