Perhaps a guide to Decrypt or Mount the disk?

**Is your feature request related to a problem? Please describe.**
I believe I have added the key to the disk, but I am confused about how can I use the key to decrypt the disk. 

**Describe the solution you'd like**
Maybe a binary that would call cryptsetup to open the disk? 

**Describe alternatives you've considered**
Provide an interface for other applications to call?

