Docs: Add default value for 'n' in MoneyModel tutorial (#2871)

Author: pragam-m25

docs/tutorials/0_first_model.ipynb

@@ -203,7 +203,7 @@
     "class MoneyModel(mesa.Model):\n",
     "    \"\"\"A model with some number of agents.\"\"\"\n",
     "\n",
-    "    def __init__(self, n, seed=None):\n",
+    "    def __init__(self, n=10, seed=None):\n",
     "        super().__init__(seed=seed)\n",
     "        self.num_agents = n\n",
     "        # Create agents\n",
@@ -251,7 +251,7 @@
     "class MoneyModel(mesa.Model):\n",
     "    \"\"\"A model with some number of agents.\"\"\"\n",
     "\n",
-    "    def __init__(self, n, seed=None):\n",
+    "    def __init__(self, n=10, seed=None):\n",
     "        super().__init__(seed=seed)\n",
     "        self.num_agents = n\n",
     "\n",
@@ -420,7 +420,7 @@
     "class MoneyModel(mesa.Model):\n",
     "    \"\"\"A model with some number of agents.\"\"\"\n",
     "\n",
-    "    def __init__(self, n):\n",
+    "    def __init__(self, n=10):\n",
     "        super().__init__()\n",
     "        self.num_agents = n\n",
     "\n",