Updated the docs

docs/play-lan.md

@@ -1,6 +1,6 @@
 # /play_lan
 
-Plays a move in long algebraic notation.
+Plays a move in Long Algebraic Notation (LAN) format.
 
 ## `color`
 

docs/play.md

@@ -0,0 +1,39 @@
+# /play
+
+Plays a move in Portable Game Notation (PGN) format.
+
+## `color`
+
+The color as per these options.
+
+- `w` for the white pieces.
+- `b` for the black pieces.
+
+## `pgn`
+
+The chess move in PGN format.
+
+---
+
+### Usage
+
+#### Example
+
+Starts a classical game to play 1.e4.
+
+```js
+ws.send('/start "{\\"variant\\":\\"classical\\",\\"mode\\":\\"analysis\\"}"');
+ws.send('/play "{\\"color\\":\\"w\\",\\"pgn\\":\\"e4\\"}"');
+```
+
+```text
+{
+  "/play": {
+    "turn": "b",
+    "movetext": "1.e4",
+    "fen": "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3",
+    "variant": "classical",
+    "isValid": true
+  }
+}
+```

mkdocs.yml

@@ -26,6 +26,7 @@ nav:
       - /heuristic: heuristic.md
       - /leave: leave.md
       - /legal: legal.md
+      - /play: play.md
       - /play_lan: play-lan.md
       - /play_rav: play-rav.md
       - /randomizer: randomizer.md