Install htdocs again. This was recently removed for an unknown (or at

least unmentioned) reason.

Crash course on populating the htdocs directory:

cd myprefix/apache-2.0
cvs checkout -d htdocs httpd-docs-2.0/htdocs


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85914 13f79535-47bb-0310-9956-ffa450edef68