DOC: Added an API contract for stocks/:userId (#203)

* added one doc for stocks api

* typo fix

* doc update fix wrt test cases

stocks/README.md

@@ -0,0 +1,90 @@
+# STOCKS
+
+| Method | Route                                           | Description                                                    |
+| ------ | ----------------------------------------------- | -------------------------------------------------------------- |
+| GET    | [/stocks/:userId](#get---stocks)                | It will fetch you all the user stocks based on your own id.    |
+
+## Stocks Object
+```
+    {
+        "message": "User stocks returned successfully!",
+        "userStocks": [
+            {
+            "id": string,
+            "userId": string,
+            "stockId": string,
+            "stockName": string,
+            "quantity": number,
+            "orderValue": number,
+            "initialStockValue": number
+            }
+        ]
+    }
+```
+
+## **GET /stocks/:userId**
+
+Returns all the stocks of the user.
+
+- **Params**
+  _Required:_ `userId=[string]`
+- **Query**
+  None
+- **Body**
+  None
+- **Headers**
+  Content-Type: application/json
+- **Cookie**
+  rds-session: `<JWT>`
+- **Success Response:**
+  - **Code:** 200
+    - **Content:**
+
+    ```
+    {
+        "message": "User stocks returned successfully!",
+        "userStocks": [
+            {
+            "id": string,
+            "userId": string,
+            "stockId": string,
+            "stockName": string,
+            "quantity": number,
+            "orderValue": number,
+            "initialStockValue": number
+            }
+        ]
+    }
+    ```
+
+When No Stock is found.
+
+  - **Code:** 200
+    - **Content:**
+
+    ```
+    { 
+      message: "No stocks found", 
+      userStocks: [] 
+    }
+    ```
+
+- **Error Response:**
+  - **Code:** 403
+    - **Content:**
+      ```
+      { 
+        'statusCode': 403,
+        'error': 'Unauthorized',
+        'message': 'Unauthorized access' 
+      }
+      ```
+  - **Code:** 500
+    - **Content:**
+      ```
+      { 
+        'statusCode': 500, 
+        'error': 'Internal Server Error', 
+        'message': 'An internal server error occurred' 
+      }
+      ```