Fix doumentation for bundled packages

docs/index.rst

@@ -8,14 +8,12 @@ Welcome to the Let's Encrypt client documentation!
    using
    contributing
    plugins
-   acme
-   letsencrypt_apache
-   letsencrypt_nginx
 
 .. toctree::
    :maxdepth: 1
 
    api
+   pkgs
 
 
 Indices and tables

docs/pkgs.rst

@@ -0,0 +1,14 @@
+========
+Packages
+========
+
+.. note:: It is planned to distribute `acme` and plugins separately as
+  described in `#358`_. For the time being those packages are bundled
+  together into a single repo, and single documentation.
+
+.. _`#358`: https://github.com/letsencrypt/lets-encrypt-preview/issues/358
+
+.. toctree::
+   :glob:
+
+   pkgs/**