Improve documentation for setup() and teardown() nose support

Fix #9549

Author: nicoddemus

doc/en/how-to/nose.rst

@@ -23,8 +23,8 @@ make use of pytest's capabilities.
 Supported nose Idioms
 ----------------------
 
-* setup and teardown at module/class/method level
-* SkipTest exceptions and markers
+* ``setup()`` and ``teardown()`` at module/class/method level: any function or method called ``setup`` will be called during the setup phase for each test, same for ``teardown``.
+* ``SkipTest`` exceptions and markers
 * setup/teardown decorators
 * ``__test__`` attribute on modules/classes/functions
 * general usage of nose utilities