To add own documentation you have to understand how a new item does appear in the menu. For this reason you have to know a little bit about the relation between doccentral and doc-base.

Debian currently has three different online documentation systems, doc-central, dwww and dhelp. All request doc-base to register documentation. This package contains utilities to manage documentation installed on Debian system. It contains a database of document metadata. Various third-party systems such as 'dwww', 'dhelp', 'doc-central' or 'scrollkeeper' use this data to provide a catalog of available
documentation.

Doc-base requires a so called control file to be able to register your own content. You will find some example control files under /usr/share/doc-base

The content should be placed under /usr/share/doc For more information see:

file:///usr/share/doc/doc-base/doc-base.html/ch-about.html

Customize doc-central

The Welcome to Doc-Central page is stored under /var/www/dc and it can be customized. The menu ist stored under /usr/share/doc-base/data in the file called scrollkeeper.map

The central location for all configurable settings in Doc-Central is in the file /usr/lib/cgi-bin/doc-central/docconfig.py