doc: markup curl as program role

See ¹.

¹: https://www.sphinx-doc.org/en/1.5/markup/inline.html#role-program

Co-authored-by: Roberto Abdelkader Martínez Pérez <robertomartinezp@gmail.com>

docs/source/the_project/quickstart.rst

@@ -150,7 +150,7 @@ Consume the Service
 +++++++++++++++++++
 
 Now we can call our newly created endpoint by using our favorite HTTP client.
-In this example we're using ``curl``:
+In this example we're using :program:`curl`:
 
 .. code-block:: console