DOCSP-12405 fix for examples (#80)

Author: kanchana-mongodb

source/reference/pipeline/lookup-stage.txt

@@ -117,11 +117,11 @@ Suppose there are three databases named ``sourceDB1``, ``sourceDB2``, and
       .. code-block:: json 
 
          db.catalog.insert([
-           { "_id" : 1, "sku" : "almonds", description: "product 1" },
-           { "_id" : 2, "sku" : "bread", description: "product 2" },
-           { "_id" : 3, "sku" : "cashews", description: "product 3" },
-           { "_id" : 4, "sku" : "pecans", description: "product 4" },
-           { "_id" : 5, "sku": null, description: "Incomplete" },
+           { "_id" : 1, "sku" : "almonds", "description": "product 1" },
+           { "_id" : 2, "sku" : "bread", "description": "product 2" },
+           { "_id" : 3, "sku" : "cashews", "description": "product 3" },
+           { "_id" : 4, "sku" : "pecans", "description": "product 4" },
+           { "_id" : 5, "sku": null, "description": "Incomplete" },
            { "_id" : 6 }
          ])
 
@@ -131,11 +131,11 @@ Suppose there are three databases named ``sourceDB1``, ``sourceDB2``, and
       .. code-block:: json 
 
          db.warehouses.insert([
-           { "_id" : 1, "stock_item" : "almonds", warehouse: "A", "instock" : 120 },
-           { "_id" : 2, "stock_item" : "pecans", warehouse: "A", "instock" : 70 },
-           { "_id" : 3, "stock_item" : "cashews", warehouse: "B", "instock" : 60 },
-           { "_id" : 4, "stock_item" : "bread", warehouse: "B", "instock" : 80 },
-           { "_id" : 5, "stock_item" : "cookies", warehouse: "A", "instock" : 80 }
+           { "_id" : 1, "stock_item" : "almonds", "warehouse": "A", "instock" : 120 },
+           { "_id" : 2, "stock_item" : "pecans", "warehouse": "A", "instock" : 70 },
+           { "_id" : 3, "stock_item" : "cashews", "warehouse": "B", "instock" : 60 },
+           { "_id" : 4, "stock_item" : "bread", "warehouse": "B", "instock" : 80 },
+           { "_id" : 5, "stock_item" : "cookies", "warehouse": "A", "instock" : 80 }
          ])
 
 The following examples use the :manual:`$lookup 
@@ -195,15 +195,15 @@ The following aggregation operation on the ``sourceDB1.orders`` collection joins
                      }
                    },
                    { 
-                     $project : { instock: 1, _id: 0} 
+                     $project : { "instock": 1, "_id": 0} 
                    }
                  ],
                  as: "wh"               
                }
              },
              { "$unwind": "$wh" },
              { 
-               $project : { description: 1, instock: "$wh.instock", _id: 0} 
+               $project : { "description": 1, "instock": "$wh.instock", "_id": 0} 
              }
            ], 
            as: "inventory"