Add reference to new paper

Update README.md

Merge branch 'devel'

bump x.y.z version to odd y following creation of RELEASE_3_22 branch

bump x.y.z version to even y prior to creation of RELEASE_3_22 branch

Update README.md

changelog

Add new vignette to discuss important parameters

Implement missing_genes option. Refactor scoring function

Update README.md

Update README.md

Update README.md

Update maintainer email

bump x.y.z version to odd y following creation of RELEASE_3_21 branch

bump x.y.z version to even y prior to creation of RELEASE_3_21 branch