Implement download feature roughly

frontend/api/routes/docs.js

@@ -34,6 +34,11 @@ router.post('/upload', (req, res) => {
   res.json(doc)
 })
 
+// Download a file.
+router.get('/download', (req, res) => {
+  res.json(db)
+})
+
 // Update a document partially.
 router.patch('/:docId', (req, res) => {
   const docIndex = db.findIndex(item => item.id === parseInt(req.params.docId))

frontend/pages/projects/_id/download/index.vue

@@ -1,9 +1,26 @@
 <template>
-  <div />
+  <v-card>
+    <v-card-title>
+      Export
+    </v-card-title>
+    <v-card-text>
+      <a :href="url" download="docs.json">Download</a>
+    </v-card-text>
+  </v-card>
 </template>
 
 <script>
 export default {
-  layout: 'project'
+  layout: 'project',
+  computed: {
+    url() {
+      const projectId = this.$route.params.id
+      return `/v1/projects/${projectId}/docs/download`
+    }
+  },
+
+  validate({ params }) {
+    return /^\d+$/.test(params.id)
+  }
 }
 </script>