[DOCS][ASFCS40] Docs currently broken on jenkins for 4.0

[Chip Childers]

Can someone from the docs team please look at the build for docs-4.0?

http://jenkins.cloudstack.org/job/docs-4.0/

Beginning work on en-US
installation-steps-overview.xml:94: validity error : Syntax of value
for attribute linkend of xref is not valid
installation-steps-overview.xml:94: validity error : IDREF attribute
linkend references an unknown ID "host-add>"
Validation failed:
Build step 'Execute shell' marked build as failure

-chip