10-print header works :)

I had to pin @thi.ng/hiccup to an earlier version because they stopped publishing CommonJS modules. There is [an issue tracking EcmaScript module support in 11ty](https://github.com/11ty/eleventy/issues/836) but it has not been fixed yet and other solutions broke unpredictably by messing with template inheritance.

package.json

@@ -10,6 +10,7 @@
     "build": "pnpm build:sass && pnpm build:eleventy",
     "watch:eleventy": "eleventy --serve --input=src/",
     "watch:sass": "ls src/**/*.{scss,sass} 2>/dev/null | entr pnpm build:sass",
+    "watch": "scripts/serve.sh",
     "start": "scripts/serve.sh"
   },
   "keywords": [],
@@ -17,6 +18,9 @@
   "license": "ISC",
   "devDependencies": {
     "@11ty/eleventy": "^1.0.0",
-    "luxon": "^2.3.0"
+    "@thi.ng/hiccup": "3.6.22",
+    "lodash": "^4.17.21",
+    "luxon": "^2.3.0",
+    "seedrandom": "^3.0.5"
   }
 }