Based on "Project: Mastermind" from The Odin Project's Ruby Course.
...........................
.... FEED_ ....
o... BACC o...
*... oo..
oo.. (a ooo.
*o.. text- oooo
**.. based *...
ooo. tribute *o..
*oo. to *oo.
**o. the *ooo
***. classic **..
oooo code- **o.
*ooo breaking, **oo
**oo game, ***.
**** Master Mind) ****
***************************
One player MAKES a CODE
as a sequence of 4 letters,
each from the set, ABCDEF.
The other player BREAKS the CODE
in a maximum of 12 guesses.
Each guess generates feedback such as
*o.. or **oo
which tallies:
* (correctly-placed letters)
o (out-of-place letters)
. (superfluous letters)