feat: created home page for Rafiki Admin (#2062)

packages/frontend/app/routes/_index.tsx

@@ -1,3 +1,27 @@
+import { version } from '../../../../package.json'
+
 export default function Index() {
-  return <></>
+  return (
+    <div className='pt-4 flex flex-col'>
+      <div className='flex flex-col rounded-md bg-offwhite px-6 text-center min-h-[calc(100vh-3rem)]'>
+        <div className='p-10 space-y-16'>
+          <h1 className='text-9xl pt-16 text-[#F37F64]'>Welcome!</h1>
+          <div className='space-y-8'>
+            <p className='text-7xl'>Rafiki Admin</p>
+            <p>This is Rafiki&apos;s administrative user interface.</p>
+            <p>v{version}</p>
+          </div>
+          <p>
+            In this web application, you&apos;ll be able to manage peering
+            relationships, assets, and payment pointers, among other settings.
+          </p>
+          <p>
+            <a href='https://rafiki.dev' className='font-semibold'>
+              https://rafiki.dev
+            </a>
+          </p>
+        </div>
+      </div>
+    </div>
+  )
 }