Regarding lack of documentation, see phishead's answer. The forum has been quite inactive since the beginning. It is currently mostly used for forum funding system proposals.
Newbie can't write reliable docs, isn't it?
Forgot to answer this. Anyway, everyone, even newbies, is entitled to make a pull request to
website to either update existing documentation or creating new documentation. Other contributors could make remarks on the pull request and suggest edits. Of course, you are correct that some knowledge is needed to work on documentation. In addition, like phishead said, in an open source project there is no central authority responsible for creating documentation. Hence, it's up to the contributors and community to create and maintain documentation.
What does it means "forum funding system proposals"? To gather money for forum's maintenance?
See smooth and nioc's answers.