nudoku: add page (#4944)

pages/common/nudoku.md

@@ -0,0 +1,36 @@
+# nudoku
+
+> Sudoku game in terminal.
+> More information: <https://jubalh.github.io/nudoku/>.
+
+- Start a sudoku game:
+
+`nudoku`
+
+- Choose the difficulty of the game:
+
+`nudoku -d {{easy|normal|hard}}`
+
+- Navigate the board:
+
+`{{h|j|k|l}} OR {{Left|Down|Up|Right}} arrow key`
+
+- Delete a number:
+
+`{{Backspace|x}}`
+
+- Get a hint:
+
+`H`
+
+- See the complete solution:
+
+`S`
+
+- Create a new puzzle:
+
+`N`
+
+- Quit the game:
+
+`Q`