Merge branch 'master' of https://github.com/hneth/unikn

update (upon CRAN release of v0.9.0)

update online documentation

update images

demo demopal() in README

add ^CRAN-SUBMISSION$ tag

update release date of version 0.4.0 to 2021-03-27

minor

bug fix (removing link to 403 page)

mention date of initial CRAN release