Han/custom homepage (#667)

* Add initial setup for custom intro page

* Add initial cards

* Add dynamic pages

* Add hrefs

Author: handotdev

docs.json

@@ -14,13 +14,14 @@
   "navigation": {
     "dropdowns": [
       {
-        "dropdown": "Getting Started",
-        "icon": "layers",
+        "dropdown": "Documentation",
+        "icon": "book",
         "description": "Set up your documentation",
         "groups": [
           {
             "group": "Getting Started",
             "pages": [
+              "introduction",
               "quickstart",
               {
                 "group": "Editing",