docs: add timeout handling example to quickstart guide

Author: Nikita20010

docs/user/quickstart.rst

@@ -59,8 +59,13 @@ You can also specify **custom headers** while making a request, for example:
     print(response.status_code)
     print(response.json())
 
-That's all well and good, but it's also only the start of what Requests can
-do.
+>>> import requests
+    >>> try:
+    ...     r = requests.get('https://httpbin.org/delay/3', timeout=2)
+    ... except requests.exceptions.Timeout:
+    ...     print("The request timed out")
+    ... else:
+    ...     print("Request completed successfully:", r.status_code)
 
 
 Passing Parameters In URLs