Warning about repod being alpha grade software

docs/index.rst:
Turn the note about repod being in a pre-release state to a warning
about it being alpha grade software.

docs/index.rst

@@ -7,10 +7,11 @@ Linux distributions using the |pacman| package manager.
 
 It is developed at https://gitlab.archlinux.org/archlinux/repod
 
-.. note::
+.. warning::
 
-   Repod is still in a pre-release state. Aside from test and development
-   setups it should not yet be used in a production environment!
+   Repod is still considered |alpha|. Aside from test and development setups it
+   is strongly recommended to not use it in a production environment at this
+   point!
 
 .. toctree::
    :maxdepth: 2
@@ -48,3 +49,7 @@ Indices and tables
 .. |pacman| raw:: html
 
   <a target="blank" href="https://archlinux.org/pacman/">pacman</a>
+
+.. |alpha| raw:: html
+
+  <a target="blank" href="https://en.wikipedia.org/wiki/Software_release_life_cycle#Alpha">alpha</a>