docs(doctest): Add refs for interlinking

Author: tony

docs/doctest/index.md

@@ -1,3 +1,6 @@
+(doctest_docutils)=
+(doctest_docutils_module)=
+
 # Doctest w/ docutils
 
 Built on {mod}`doctest`.

docs/doctest/pytest.md

@@ -1,3 +1,6 @@
+(pytest_plugin)=
+(pytest_doctest_docutils)=
+
 # pytest plugin
 
 :::{note}
@@ -6,7 +9,7 @@ This plugin disables pytest's standard `doctest` plugin.
 
 :::
 
-The pytest plugin is built on top of the doctest_docutils module, which is in
+The pytest plugin is built on top of the `doctest_docutils` module, which is in
 turn compatible with {mod}`doctest`.
 
 ## Markdown