chore(vercel): add redirects for overview for v6 and v7

Author: brandyscarney

vercel.json

@@ -5,6 +5,10 @@
       "source": "/docs/angular",
       "destination": "/docs/angular/overview"
     },
+    {
+      "source": "/docs/:version(v6|v7)/angular",
+      "destination": "/docs/:version/angular/overview"
+    },
     {
       "source": "/docs/angular/your-first-app/2-taking-photos",
       "destination": "/docs/angular/your-first-app/taking-photos"
@@ -44,6 +48,10 @@
       "source": "/docs/react",
       "destination": "/docs/react/overview"
     },
+    {
+      "source": "/docs/:version(v6|v7)/react",
+      "destination": "/docs/:version/react/overview"
+    },
     {
       "source": "/docs/react/your-first-app/2-taking-photos",
       "destination": "/docs/react/your-first-app/taking-photos"
@@ -69,6 +77,10 @@
       "source": "/docs/vue",
       "destination": "/docs/vue/overview"
     },
+    {
+      "source": "/docs/:version(v6|v7)/vue",
+      "destination": "/docs/:version/vue/overview"
+    },
     { "source": "/docs/vue/your-first-app/2-taking-photos", "destination": "/docs/vue/your-first-app/taking-photos" },
     { "source": "/docs/vue/your-first-app/3-saving-photos", "destination": "/docs/vue/your-first-app/saving-photos" },
     { "source": "/docs/vue/your-first-app/4-loading-photos", "destination": "/docs/vue/your-first-app/loading-photos" },