prepare crksm for release

[castagnotto]

hi @mariacruzvarona @Paul70

I am planning on adding MIMO and global CIRKA to sssMOR for a release shortly before the MathMod conference in Vienna. In this context we should assess whether to include CRKSM (and related functions) to the release as well, since you have been working hard on it and it would be nice to have it!

I will add an issue per function to make sure that

• formatting
• documentation
• testing

are all in place before the release. Functions that don't meet this requirement will have to be considered in a later release (right now, I am not even sure if I will be able to clean up my functions on time, but we will see 😉)

Once you have completed the three tasks, just close the issue.

All the best from Frankfurt

Ale