some comments

flake.nix

@@ -5,6 +5,8 @@
   let
     pkgs = nixpkgs.legacyPackages.x86_64-linux;
 
+    # toolchain is an environment with the specified packages
+    # rootfs will contain all binaries given by toolchain
     toolchain = pkgs.buildEnv {
       name = "pigeon-toolchain";
       paths = with pkgs; [ bash coreutils gcc gnumake util-linux ];
@@ -31,6 +33,7 @@
       mkfs.ext4 -q -F -d rootfs $out "1G"
     '';
 
+    # minimal kernel build, see firecracker documentation for needed params
     kernel-params = [
       "64BIT" "TTY" "SERIAL_8250" "SERIAL_8250_CONSOLE" "PRINTK"
       "HYPERVISOR_GUEST" "PARAVIRT" "KVM_GUEST"
@@ -80,6 +83,7 @@
         (builtins.readFile ./pigeon.sh);
     };
 
+    # see webhook documentation for hooks
     hooks = pkgs.writeText "pigeon-hooks.json" (builtins.toJSON [
       {
         id = "release";