diff --git a/dlgr/griduniverse/csv_gridworlds.py b/dlgr/griduniverse/csv_gridworlds.py
index c21442ba..b5cf66bf 100644
--- a/dlgr/griduniverse/csv_gridworlds.py
+++ b/dlgr/griduniverse/csv_gridworlds.py
@@ -10,6 +10,25 @@
 def matrix2gridworld(matrix):
     """Transform a 2D matrix representing an initial grid state
     into the serialized format used by Gridworld.
+
+    Example:
+
+    +---------------+---------+--------------------+
+    | w             | stone   | gooseberry_bush|3  |
+    | p1c1          | w       | w                  |
+    |               |         | p3c2               |
+    |               | p4c2    |                    |
+    | big_hard_rock | w       | p2c1               |
+    +---------------+---------+--------------------+
+
+    Explanation:
+
+    - "w": a wall
+    - "stone": item defined by item_id "stone" in game_config.yml
+    - "gooseberry_bush|3": similar to the above, with the added detail
+        that the item has 3 remaining uses
+    - "p2c1": player ID 2, who is on team (color) 1
+    - Empty cells: empty space in the grid
     """
     result = defaultdict(list)
 
diff --git a/package.json b/package.json
index 935e8859..ac54df54 100644
--- a/package.json
+++ b/package.json
@@ -50,5 +50,6 @@
   "bugs": {
     "url": "https://github.com/Dallinger/Griduniverse/issues"
   },
-  "homepage": "https://github.com/Dallinger/Griduniverse#readme"
+  "homepage": "https://github.com/Dallinger/Griduniverse#readme",
+  "packageManager": "yarn@1.22.22+sha512.a6b2f7906b721bba3d67d4aff083df04dad64c399707841b7acf00f6b133b7ac24255f2652fa22ae3534329dc6180534e98d17432037ff6fd140556e2bb3137e"
 }