util/_file_util library

1. hb_rename package
2. documentation
3. util/_file_util.dart

hb_rename package

1. Libraries
2. command/hb_rename_command
3. hb_rename
4. template/_template
5. util/_android_tool
6. util/_file_util
7. util/_ios_tool
8. util/_lib_tool
9. util/_macos_tool