Add codeblocks for requests and responses

docs/tutorial/quickstart.md

@@ -169,7 +169,11 @@ We're now ready to test the API we've built.  Let's fire up the server from the
 
 We can now access our API, both from the command-line, using tools like `curl`...
 
-    bash: curl -H 'Accept: application/json; indent=4' -u admin:password123 http://127.0.0.1:8000/users/
+```bash
+curl -H 'Accept: application/json; indent=4' -u admin:password123 http://127.0.0.1:8000/users/
+```
+
+```json
 {
     "count": 2,
     "next": null,
@@ -189,13 +193,20 @@ We can now access our API, both from the command-line, using tools like `curl`..
         }
     ]
 }
+```
 
 Or using the [httpie][httpie], command line tool...
 
-    bash: http -a admin:password123 http://127.0.0.1:8000/users/
+```bash
+http -a admin:password123 http://127.0.0.1:8000/users/
+```
 
+```text
 HTTP/1.1 200 OK
 ...
+```
+
+```json
 {
     "count": 2,
     "next": null,
@@ -215,7 +226,7 @@ Or using the [httpie][httpie], command line tool...
         }
     ]
 }
-
+```
 
 Or directly through the browser, by going to the URL `http://127.0.0.1:8000/users/`...