disko: add initial config

disko/README.md

@@ -0,0 +1,27 @@
+##Step by step##
+1. Boot the [installer](https://nixos.org/download.html#nixos-iso)
+
+2. Get disk name 
+```$ lsblk```
+
+3. Get disko config
+```
+$ curl https://git.kabtop.de/Kabbone/nixos-config/raw/branch/main/disko/btrfs_luks.nix -o /tmp/disko-config.nix
+```
+
+4. Adjust device name
+
+5. Let disko partition the disk
+```
+$ sudo nix --experimental-features "nix-command flakes" run github:nix-community/disko -- --mode disko /tmp/disko-config.nix
+```
+
+6. Check if it got mounted
+```$ mount | grep /mnt```
+
+7. Continue with NixOS installation
+Filesystem definitions come from disko, hence "--no-filesystems"
+`Alternative:` continue with normal hardware-config
+```
+$ nixos-generate-config --no-filesystems --root /mnt
+$ mv /tmp/disko-config.nix /mnt/etc/nixos