Add Docker Compose deployment

README.md

@@ -11,13 +11,27 @@ A notepad-playable browser game that combines Tic Tac Toe's line-making goal wit
 - First player to make `4 in a row` wins.
 - If the board fills with no winner, the game is a draw.
 
-## Run Multiplayer
+## Run With Docker Compose
+
+```powershell
+docker compose up --build
+```
+
+Then open `http://localhost:3000` in two browser windows. The first two connected players are paired automatically.
+
+Stop it with:
+
+```powershell
+docker compose down
+```
+
+## Run Locally
 
 ```powershell
 npm start
 ```
 
-Then open `http://localhost:3000` in two browser windows. The first two connected players are paired automatically.
+Then open `http://localhost:3000` in two browser windows.
 
 Set a different port with: