Deleted Macintosh HD. Need to create a new partition/ partition table
Boot to Recovery HD (or Internet Recovery) and then use Disk Utility to format the drive(s) as part of this documented process to erase and install the OS.


https://support.apple.com/kb/PH21973


Booting from recovery is what makes the partition map writeable. You were very close to the solution. If erasing doesn't work, you may have to repartition the volume per https://support.apple.com/kb/PH22240

As a last resort, boot to single user mode and/or Recovery and start terminal and get a screen capture/picture/verbatim listing of the output of:

diskutil list