update header with dropdown for secondary pages & add missing basic routes and pages

src/pages/Contact.vue

@@ -0,0 +1,12 @@
+<template>
+  <component-debug :component="this" />
+</template>
+
+<script>
+export default {
+  name: 'Contact'
+}
+</script>
+
+<style lang="scss" scoped>
+</style>

src/pages/Introduction.vue

@@ -0,0 +1,12 @@
+<template>
+  <component-debug :component="this" />
+</template>
+
+<script>
+export default {
+  name: 'Introduction'
+}
+</script>
+
+<style lang="scss" scoped>
+</style>