Revert "readme.md: refine text about windres.exe."

This reverts commit 39d9152a9e6823de13bf71768a1a724408707940.
Revert "update readme.md about make.cmd resource and not always MinGW required."

This reverts commit 0fda897aa5b07c8b3361245d8204f87d9f85fb5b.
built-in mkdir/rmdir
create built-in command: del,erase
rmdir: remove duplicate of wildcard expansion
built-in del: modify prompt and message