generate URLs for all demos and use those to run the tests

docs/src/templates/DemoPage/index.vue

@@ -0,0 +1,23 @@
+<template>
+  <div class="demo-page">
+    <demo :name="$context.name" :show-source="false" />
+  </div>
+</template>
+
+<script>
+export default {
+  metaInfo() {
+    return {
+      title: this.$context.name,
+      meta: [
+        {
+          name: 'robots',
+          content: 'noindex',
+        },
+      ],
+    }
+  },
+}
+</script>
+
+<style lang="scss" src="./style.scss" scoped></style>