Clarify how specifying individual scenarios works

Author: npilon

README.rst

@@ -139,7 +139,8 @@ Invoking Tests
 You can run tests by allowing nose2's autodiscovery to find all of your tests,
 or you can specify specific tests to be run on the command line. When
 specifying specific tests, you can either specify an entire package,
-an entire feature, or individual scenarios.
+an entire feature, or individual scenarios. Individual scenarios can be
+specified either by index (from 0) or by name.
 
 .. code::
 
@@ -149,3 +150,7 @@ an entire feature, or individual scenarios.
     nose2 planterbox.tests.test_feature:basic.feature:0
     nose2 planterbox.tests.test_feature:basic.feature:"I need to verify basic arithmetic"
     nose2 planterbox.tests.test_feature:basic.feature:"I need to verify basic arithmetic."
+
+If your feature includes multiple scenarios with the same name, all will be
+run when that name is given. Names with a trailing period can be specified with
+or without the trailing period.