Take a look at how Robin's 'Several Things' thread is structured:
First there is a warning to noobs - 'The useful information is in the first two posts only. All that follows is noisy discussion'.
Then the current listing of the program.
Then 'official' explanations and notes.
Then the 'noisy' discussion.
I think this is a very useful way to work within a forum environment for developing a consensus document based on a single member's vision. If you have read it all the way through, you'll see that ideas presented in the discussion were incorporated into the 'official' part of the thread - that is, the code listing was updated in the first post of the thread.
You would be able to do something similar with a FAQ. Put together the best FAQ you can, and post it in a new thread. Discussion will follow. As the 'keeper of the FAQ' you would be able to merge the useful parts of that discussion into the FAQ. You will be the only one able to edit changes into the first post, and will have control of what goes into that post. (Moderation notwithstanding.) Build the FAQ in the first post of your thread.
Finally add the warning, identifying the official FAQ part (your first post, and an optional follow-up post) and the 'rabble' part (all the discussion that follows. - it not really rabble, this is where the fine tuning, and consensus happens.)
I believe this would be much more acceptable to the group here than a Github repository. You know - homegrown vs an offsite resource and population. Forum denizens tend to trust others on the same forum more so than the internet population in general.
The key in this scheme is that you are the sole editor if your original post. Once the document becomes truly beneficial, petition the mods to pin it.