A few simple steps allow your addon to be installed directly from GitHub releases with WoWUp and Ajour independent updaters. Here's my notes on how I added it to mine:

https://gist.github.com/SpareSimian/c91f5f0261a11f030c363553f685ab71

I also recommend adding "topics" to make it easier to find your addon in GitHub searches. I use world-of-warcraft and wow-addon. Click the gear icon at top right of your GitHub addon page above the About text to set topics.

Thanks for your advice.
I'm already using automated publishing script (Powershell) for my addons. You can find it in my AddonUploader repo. It can be run locally and supports also a "dry run" so I can check the resulting archive without actual publishing. It only supports Curseforge at the moment, but I'm going to add other updaters once.