KDE Documentation Primer error

[John Hayes]

In https://l10n.kde.org/docs/doc-primer/writing-docs.html
Chapter 4. Writing Documentation: Procedures and Tools

Now you reached the list of files that are part of Lokalize's documentation,
including images and DocBook sources. The DocBook sources are files in the
format *.docbook. In this case, there is only one file file in this format:

      ^^^^^^
index.docbook. Click this file on the list and the content of that
file will be displayed.