modules: move options to the top

This greatly improves readability and makes it easier to discover options.

This commit was genereated by running the following script inside the
repo root dir:

#!/usr/bin/env ruby

def transform(src)
  return false if src.include?('inherit options;')

  success = false

  options = nil
  src.sub!(/^  options.*?^  }.*?;/m) do |match|
    options = match
    "  inherit options;"
  end
  return false if !options

  src.sub!(/^with lib;\s*let\n+/m) do |match|
    success = true
    <<~EOF
      with lib;
      let
      #{options}

    EOF
  end

  success
end

Dir['modules/**/*.nix'].each do |f|
  src = File.read(f)
  if transform(src)
    puts "Changed file #{f}"
    File.write(f, src)
  end
end

modules/lightning-pool.nix

@@ -1,27 +1,7 @@
 { config, lib, pkgs, ... }:
 
 with lib;
-
 let
-  cfg = config.services.lightning-pool;
-  nbLib = config.nix-bitcoin.lib;
-
-  lnd = config.services.lnd;
-
-  network = config.services.bitcoind.network;
-  rpclisten = "${cfg.rpcAddress}:${toString cfg.rpcPort}";
-  configFile = builtins.toFile "pool.conf" ''
-    rpclisten=${rpclisten}
-    restlisten=${cfg.restAddress}:${toString cfg.restPort}
-    ${optionalString (cfg.proxy != null) "proxy=${cfg.proxy}"}
-
-    lnd.host=${lnd.rpcAddress}:${toString lnd.rpcPort}
-    lnd.macaroondir=${lnd.networkDir}
-    lnd.tlspath=${lnd.certPath}
-
-    ${cfg.extraConfig}
-  '';
-in {
   options.services.lightning-pool = {
     enable = mkEnableOption "lightning-pool";
     rpcAddress = mkOption {
@@ -79,6 +59,27 @@ in {
     enforceTor = nbLib.enforceTor;
   };
 
+  cfg = config.services.lightning-pool;
+  nbLib = config.nix-bitcoin.lib;
+
+  lnd = config.services.lnd;
+
+  network = config.services.bitcoind.network;
+  rpclisten = "${cfg.rpcAddress}:${toString cfg.rpcPort}";
+  configFile = builtins.toFile "pool.conf" ''
+    rpclisten=${rpclisten}
+    restlisten=${cfg.restAddress}:${toString cfg.restPort}
+    ${optionalString (cfg.proxy != null) "proxy=${cfg.proxy}"}
+
+    lnd.host=${lnd.rpcAddress}:${toString lnd.rpcPort}
+    lnd.macaroondir=${lnd.networkDir}
+    lnd.tlspath=${lnd.certPath}
+
+    ${cfg.extraConfig}
+  '';
+in {
+  inherit options;
+
   config = mkIf cfg.enable {
     services.lnd.enable = true;