Update document of cleanup command
tree379f297941c6e213a8d12bbec68d7f759d293c18
-rw-r--r-- 367 .gitignore
-rw-r--r-- 543 .gitmodules
drwxr-xr-x - Languages
-rw-r--r-- 3400 build.txt
drwxr-xr-x - common
drwxr-xr-x - contrib
drwxr-xr-x - doc
drwxr-xr-x - ext
-rw-r--r-- 184 release.txt
drwxr-xr-x - src
drwxr-xr-x - test