Add build and build-adoc scripts

modules/scripts/build.nix

@@ -0,0 +1,16 @@
+{
+  flake.modules.homeManager.base =
+    { pkgs, ... }:
+    {
+      home.packages = [
+        (pkgs.writeShellApplication {
+          name = "build";
+
+          text = ''
+            test -r book/index.adoc && exec build-adoc "$@"
+            test -x build && exec ./build "$@"
+          '';
+        })
+      ];
+    };
+}