Describe workaround for v3.18 on aarch64 and test it on CI

.github/workflows/ci.yml

@@ -121,9 +121,9 @@ jobs:
         run: |
           ./alpine-make-vm-image \
               --arch aarch64 \
+              --branch edge \
               --image-format qcow2 \
               --image-size 2G \
-              --repositories-file example/repositories \
               --packages "$(cat example/packages)" \
               --fs-skel-dir example/rootfs \
               --fs-skel-chown root:root \

README.adoc

@@ -12,13 +12,13 @@ This project provides a script for making customized https://alpinelinux.org/[Al
 You can choose between BIOS mode (using https://syslinux.org/[Syslinux], only for x86_64) and UEFI mode (using Linux https://docs.kernel.org/admin-guide/efi-stub.html[EFI stub]).
 It’s quite simple (400 LoC of shell), fast (~32 seconds on GitHub Actions), requires minimum dependencies (QEMU and filesystem tools).
 
+IMPORTANT: aarch64 currently only works with the kernel (linux-virt or linux-lts) from Alpine edge! See <<aarch64-v3.18>> for more information and a workaround.
+
 TIP: Don’t need VM, just wanna chroot into Alpine Linux?
      Try https://github.com/alpinelinux/alpine-chroot-install[alpine-chroot-install]!
      Or do you want to create a custom rootfs?
      Then https://github.com/alpinelinux/alpine-make-rootfs[alpine-make-rootfs] is for you!
 
-IMPORTANT: aarch64 currently only works with the kernel (linux-virt or linux-lts) from Alpine edge! See <<aarch64-v3.18>> for more information and a workaround.
-
 
 == Requirements