Add argument for archiving sub-directories in path.

Make an archiving of sub-directories relative to path.
i.e.
```bash
archive example
```
where example has subdirs: 
- example_sub1
- example_sub2

Script should do:

1. Check if there is --subdirectory argument
2. List subdirectories in *path* directory
3. Tar all subdirectories and remove them.