Prepare the package for the 2.9.0 release

Prepare the package for the 2.8.2 release and pretest TeX Live 2020

Properly typeset math subscripts in the documentation

Prepare the package for the 2.8.0 release

Prepare the package for the 2.7.0 release

Prepare the package for the 2.6.0 release

Prepare the package for the 2.5.6 release

Prepared the package for the 2.5.5 release.

Prepared the package for the 2.5.4 release. (closes Witiko#12)

Replaced tux in the examples with a generic example image.