Clean up docs issues

The Sphinx build produces a number of warnings and errors. Some are
rightfully ignored, but many need to be fixed. These are mostly
unindexed pages and misformatted references.

Signed-off-by: Eric Ball <eball@linuxfoundation.org>
Change-Id: I9d7a116dc87083ad2dcab20e31cd479364f298cd
diff --git a/howto/release/charts/voltha-openonu-adapter.rst b/howto/release/charts/voltha-openonu-adapter.rst
index bd4ad85..4683158 100644
--- a/howto/release/charts/voltha-openonu-adapter.rst
+++ b/howto/release/charts/voltha-openonu-adapter.rst
@@ -65,4 +65,4 @@
 
 .. seealso::
 
-`voltha-docs::charts <../charts/index>`
+   `voltha-docs::charts <../charts/index>`