Feature: New game "Nine men's morris"

[Kesuaheli]

The game nine men's morris (ger: "Mühle") would be a great addition for the bot.

For the board something like this would work

⬛⬜⬜⬜⬜⬜⬛⬜⬜⬜⬜⬜⬛7️⃣
⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜🟦
⬜⬜⬛⬜⬜⬜⬛⬜⬜⬜⬛⬜⬜6️⃣
⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜🟦
⬜⬜⬜⬜⬛⬜⬛⬜⬛⬜⬜⬜⬜5️⃣
⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜🟦
⬛⬜⬛⬜⬛⬜⬜⬜⬛⬜⬛⬜⬛4️⃣
⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜🟦
⬜⬜⬜⬜⬛⬜⬛⬜⬛⬜⬜⬜⬜3️⃣
⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜🟦
⬜⬜⬛⬜⬜⬜⬛⬜⬜⬜⬛⬜⬜2️⃣
⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜🟦
⬛⬜⬜⬜⬜⬜⬛⬜⬜⬜⬜⬜⬛1️⃣
🇦🟦🇧🟦🇨🟦🇩🟦🇪🟦🇫🟦🇬

However, using black and white as board colors also mean they wouldn't work for the color of the men, which are typically black (or real dark brown) an white (or real bright brown).
If you use custom emojis then the horizontal and vertical lines between the black dots can be drawn for better movement visualization. Also, a custom backgorund color (like a bright-yellow-ish?) would be possible to avoid using white, which allows one of the players to be ⚪ and the other to be 🟤.
By the way, the board alone uses 195 emojis, allowing 4 more to use: Two for player identification (e.g. Player1 (⚪) vs. Player2 (🟤)), one for the game state (e.g. It's Player1 (⚪) turn), and one for spare(?)

For the operations I thought of a similar control like in chess. Select one of your men and his destination with [A-G][1-7].
This also allows a good control for the placing and the "flying" (aka. hopping, jumping) phase, as well as selecting a opponent's man after a mill was formed.