Added redirect and modified api reference section

docs/source/reference/api/spawner.md

@@ -0,0 +1,20 @@
+# Spawners
+
+## Module: {mod}`jupyterhub.spawner`
+
+```{eval-rst}
+.. automodule:: jupyterhub.spawner
+```
+
+### {class}`Spawner`
+
+```{eval-rst}
+.. autoconfigurable:: Spawner
+   :members: options_from_form, poll, start, stop, get_args, get_env, get_state, template_namespace, format_string, create_certs, move_certs
+```
+
+### {class}`LocalProcessSpawner`
+
+```{eval-rst}
+.. autoconfigurable:: LocalProcessSpawner
+```