docs(elements): add link to full example in `elements` guide (#25219)

PR Close #25219

aio/content/examples/elements/stackblitz.json

@@ -0,0 +1,9 @@
+{
+  "description": "Angular Elements",
+  "files":[
+    "!**/*.d.ts",
+    "!**/*.js",
+    "!**/*.[1].*"
+  ],
+  "tags":["cookbook"]
+}

aio/content/guide/elements.md

@@ -158,3 +158,9 @@ For comparison, the demo shows both methods. One button adds the popup using the
 
   </code-pane>
 </code-tabs>
+
+<!--
+  StackBlitz transpiles code to ES5. The live example will not work without a polyfill.
+  Only offer a `.zip` to download for now.
+-->
+You can download the full code for the example <live-example downloadOnly>here</live-example>.

aio/tools/example-zipper/customizer/package-json/elements.json

@@ -0,0 +1,21 @@
+{
+  "scripts": [
+    { "name": "ng", "command": "ng" },
+    { "name": "build", "command": "ng build" },
+    { "name": "start", "command": "ng serve" },
+    { "name": "test", "command": "ng test" },
+    { "name": "lint", "command": "ng lint" },
+    { "name": "e2e", "command": "ng e2e" }
+  ],
+  "dependencies": [
+    "@angular/elements"
+  ],
+  "devDependencies": [
+    "@angular-devkit/build-angular",
+    "@angular/cli",
+    "@types/jasminewd2",
+    "jasmine-spec-reporter",
+    "karma-coverage-istanbul-reporter",
+    "ts-node"
+  ]
+}