Add MKS Monster 8 generic config

[Bomberski]

Adding MKS Monster 8 generic configuration

Signed-off-by: Allen Cox Bomberski420@gmail.com

[Bomberski]

I believe that's default speed?

Thanks, first pull request ever. Had to figure this all out. Thanks for the pleasant experience!

[JamesH1978]

#   Maximum velocity (in mm/s) of the stepper when homing. The default
#   is 5mm/s.``` :) but most example configs set 50

Thanks
James

[Bomberski]

#   Maximum velocity (in mm/s) of the stepper when homing. The default
#   is 5mm/s.``` :)

I will swap from 50 to 5, thank you

[JamesH1978]

and i meant change = to : on all those option in heater_bed, and i edited my reply to say 50 is fine, it used in most example.

Thanks James

[KevinOConnor]

Thanks.

-Kevin