Revert "remove useless files"

This reverts commit b884bbbfac09e3aa2823b086dde0af9a98e892fd.
add note.txt
Revert "Revert "remove useless files""

This reverts commit 0f83f1106ef426bd4b7d69a1485dafafb07ccbb9.
Update and rename note.txt to postfix.txt

Add some knowledge about postfix
Merge pull request #74 from zlroy1023/master

commit