Remove flake-compat, add readme

flake-compat is a kind of unhelpful thing to add here since it makes it
impossible to update lix separately from its module when not using
flakes. We would like non-flakes users to not use the flake by using
module.nix directly.

README.md

@@ -0,0 +1,5 @@
+# Lix NixOS module
+
+See the [beta guide][beta-guide] for details on how to use this:
+
+[beta-guide]: https://wiki.lix.systems/link/1

default.nix

@@ -1,10 +0,0 @@
-(import
-  (
-    let lock = builtins.fromJSON (builtins.readFile ./flake.lock); in
-    fetchTarball {
-      url = lock.nodes.flake-compat.locked.url or "https://git.lix.systems/lix-project/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
-      sha256 = lock.nodes.flake-compat.locked.narHash;
-    }
-  )
-  { src = ./.; }
-).defaultNix

flake.lock

@@ -1,20 +1,5 @@
 {
   "nodes": {
-    "flake-compat": {
-      "locked": {
-        "lastModified": 1696426674,
-        "narHash": "sha256-kvjfFW7WAETZlt09AgDn1MrtKzP7t90Vf7vypd3OL1U=",
-        "ref": "refs/heads/master",
-        "rev": "0f9255e01c2351cc7d116c072cb317785dd33b33",
-        "revCount": 57,
-        "type": "git",
-        "url": "ssh://git@git.lix.systems/lix-project/flake-compat"
-      },
-      "original": {
-        "type": "git",
-        "url": "ssh://git@git.lix.systems/lix-project/flake-compat"
-      }
-    },
     "flake-utils": {
       "inputs": {
         "systems": "systems"
@@ -82,7 +67,6 @@
     },
     "root": {
       "inputs": {
-        "flake-compat": "flake-compat",
         "flake-utils": "flake-utils",
         "flakey-profile": "flakey-profile",
         "lix": "lix",

flake.nix

@@ -5,7 +5,6 @@
     flake = false;
   };
   inputs.flake-utils.url = "github:numtide/flake-utils";
-  inputs.flake-compat.url = "git+ssh://git@git.lix.systems/lix-project/flake-compat";
   inputs.flakey-profile.url = "github:lf-/flakey-profile";
 
   outputs = inputs@{ self, nixpkgs, lix, flake-utils, flakey-profile, ... }: