Installation fails for pkuthss on Windows

[Akira Kakuto]

Dear Phelype,

> Running `tlmgr install pkuthss` fails (error messages at the botom
> of this email) because (apparently) the program tries to create a
> folder 'readme', but fails on Windows (apparently is case-insensitive)
> because the name is already taken by the file 'README'.

Fixed in the latest pkuthss, and in the TeX Live.
README is now README.txt

Best,
Akira