doc: document aliases of tests stanza

Signed-off-by: Ali Caglayan <[email protected]>

Author: Alizter

doc/reference/dune/test.rst

@@ -26,11 +26,13 @@ can define two tests at once with:
     (names mytest expect_test)
     <optional fields>)
 
-This defines an executable named ``mytest.exe`` that will be executed as part of
-the ``runtest`` alias. If the directory also contains an
-``expect_test.expected`` file, then ``expect_test`` will be used to define an
-expect test. That is, the test will be executed and its output will be compared
-to ``expect_test.expected``.
+This defines an executable named ``mytest.exe``. These tests can be run by
+building the aliases ``mytest`` and ``expect_test`` respectively. They will also
+be added to the ``runtest`` alias.
+
+If the directory also contains an ``expect_test.expected`` file, then
+``expect_test`` will be used to define an expect test. That is, the test will be
+executed and its output will be compared to ``expect_test.expected``.
 
 The optional fields supported are a subset of the alias and executables fields.
 In particular, all fields except for ``public_names`` are supported from the