With your skillset, you could be doing invaluable work by writing documentation.
The world is full of good Free software that is essentially orphaned, because the documentation is practically useless. Many moribund projects could be revitalised with little more than a concise description of what the software does, why you might choose it over the alternatives, and how to get started.
Other projects suffer from dreadfully myopic documentation, with a wiki full of detailed descriptions of weird minutiae, but little that would be of use to newcomers. Few developers can write well, and even fewer have the insight to view their project from an outsider's perspective.
I have a similar skillset to OP, and I was brought on board to write/improve the documentation for http://www.fluentd.org/
I'm now unable to devote nearly as much time to the project as before, so there's definitely a need in the project right now. The tool is used by AWS, Google Cloud Platform, LINE, Nintendo and others, so it's something that would have wide reach right away.
Documentation often gets cited as the main 'semi-techncal' thing to do for an open-source project.
However, I disagree with the point that moribund projects could be revitalised this way. If the people writing the code have little interest in explaining to other people like themselves how to use it then IMHO writing additional text for less involved people is not going to be very impactful.
Your second point about myopic docs is spot on, though. A human-readable summary can be invaluable but it involves getting your head around what already exists first -- that requires some will from the developers in the first place.
I actually ran into this issue with the `argus` network flow generator/processor project, run "by one dude." As a non-developer, but a user, I spent time grinding away at understanding it, mostly as a hobby, and wound up realizing that the "one dude" set his bar pretty high at what he expected of his users' skill sets. I can sincerely appreciate that, but that bar should be lowered so that folks can at least use the software effectively without pissing off the entire mailing list :D
I did just as stated here; lowered the bar for non-developers by producing "on boarding" documentation that takes you from no-to-go in about 30 minutes, massaging my inane questions and failures in mailing list etiquette into an accessible wiki doc (accessible at nsmwiki.org for anyone who is specifically interested).
The world is full of good Free software that is essentially orphaned, because the documentation is practically useless. Many moribund projects could be revitalised with little more than a concise description of what the software does, why you might choose it over the alternatives, and how to get started.
Other projects suffer from dreadfully myopic documentation, with a wiki full of detailed descriptions of weird minutiae, but little that would be of use to newcomers. Few developers can write well, and even fewer have the insight to view their project from an outsider's perspective.