I have just started to review the Libre Office documentation. I have seen the information to the effect that you are looking for people who can help out. I have a MA in Linguistics and years of experience in technical writing, which I also taught for a while. I would like to volunteer. My talents are currently not used much, and I can help you out. I will also help myself out by learning the details of the Libre Office documentation.
Great to have you join us. Experienced tech writers are especially welcome, because we need people to research and write as well as people to review and edit. If you haven't already seen this page, it's a good place to start even though a few details are out of date.
https://wiki.documentfoundation.org/Documentation/Development
--Jean