README.md: fix typo and add sign WIP, which means Work In Progress
Revert "README.md: fix typo and add sign WIP, which means Work In Progress"

This reverts commit 80b33940bc65357f9493b8cb208cab9dbe9e9abe.

fix <LF> changing to <CRLF>
README.md: add WIP sign and finish 10.c