We have moved from GitHub to a self-hosted Gitea instance to allow better control over the storage and a faster uplink for me to commit (on my local network!)
You can find it here:
https://alpinekobox.ddns.net
I got a working instance running on a Kobo Glo HD and it could've worked, but the main problem was storage and wear, so I opted for a small thin client instead with a 40GB HDD. This should be enough to build the aports tree for the main repository, and I'll probably upgrade the storage soon.
I'll compile most of the packages on my Raspberry Pi and I'll post scripts to bootstrap a proper minirootfs of self-built Alpine Linux.
You can always help by compiling (on your Kobo, or Raspberry Pi, or with some cross-compiling fairy dust

) other packages from other repositories (I'll publish a guide for that) or come discussing over on Discord.
@fermino proposed to host a mirror website with faster D/L speeds, so we'll set that up soon. (btw, thanks)
Any questions? you can ask them on Discord (see Elektron's signature for the link or one of my previous posts in this thread) or here.