Commit Alpine.js to the repo instead of unpacking it at build time (closes #163)

static/js/alpine.min.js is now committed: package/dist/cdn.min.js from
the @alpinejs/csp 3.14.9 npm package, byte for byte, taken once from the
package file that was in 3p/. The build no longer unpacks it, so
script/assets, the assets make target, its Dockerfile steps and the
ignore entries for the file are gone, and so is the package file.
Prettier and ESLint both ignore the file, so it stays as published.
Comments and the README now describe the committed file.

Model: opus-5-5

internal/server/static_assets_test.go

@@ -13,9 +13,6 @@ import (
 
 // TestBaseTemplateScriptsAreServed walks every /s/ script the base
 // template loads on each page and fetches it through the real router.
-// Alpine.js is extracted from its tarball in 3p/ at build time, so the
-// file is not in the tree: this is the check that the page still gets
-// the JavaScript it asks for.
 func TestBaseTemplateScriptsAreServed(t *testing.T) {
 	t.Parallel()