New submission

fixed HTML validation problems discovered by CRAN checks
fixed NEWS.md to follow CRAN format
failing tests on "r-oldrel-windows-ix86+x86_64" are due to the lack of MatrixExtra library. I'm not sure why this happened on CRAN server

Test environments

laptop OS X, R 4.0.5
win-builder (devel)

R CMD check results

One misc note which shows 403 error when accessing http://yifanhu.net/PUB/cf.pdf. This seems CRAN server specific.