docs: add odl external wallet docs as placeholder

Author: ElasticBottle

apps/portal/src/app/connect/sidebar.tsx

@@ -134,7 +134,7 @@ export const sidebar: SideBar = {
                 },
                 {
                   name: "External Wallets",
-                  href: `${connectSlug}/methods/external-wallets`,
+                  href: `${walletSlug}/sign-in-methods/external-wallets`,
                 },
                 {
                   name: "Custom Authentication",

apps/portal/src/app/connect/wallet/sign-in-methods/external-wallets/page.mdx

@@ -0,0 +1,26 @@
+# External wallets
+
+thirdweb supports a number of first-party web3 wallets such as Metamask and Phantom. 
+
+## Add externally owned wallets
+
+```tsx
+import { ConnectButton } from "thirdweb/react";
+import { createWallet } from "thirdweb/wallets";
+ 
+const wallets = [
+  createWallet("io.metamask"),
+  createWallet("com.coinbase.wallet"),
+  createWallet("me.rainbow"),
+];
+ 
+function Example() {
+  return (
+    <div>
+      <ConnectButton client={client} wallets={wallets} />
+    </div>
+  );
+}
+```
+
+[View full list of supported wallets.](/typescript/v5/supported-wallets)