Update to Chapter 3 of Contributor document

Howdy again,

So, while at it I grabbed a copy of Chatper 3 and renamed it to 3 - Using
the LibreOffice Documentation Team Website.odt.

Again a fairly straight forward exchange of ODFAuthors for TDF NextCloud
[sever] or LibreOffice Documentation Team workspace was all I did at the
moment.

Also, changed some of the copyright material so reference the old chapter 3
as the basis for this work, moved contributors to prior status..etc.

The direct link to the file in the workgroup folder is
https://nextcloud.documentfoundation.org/f/88194

Best wishes,

Drew