feat: Add Account app MFA instructions

docs/unraid-account/multi-factor-authentication.mdx

@@ -0,0 +1,42 @@
+---
+title: Multi-factor Authentication
+description: How to enable or disable MFA for your Unraid account
+---
+
+Multi-factor authentication (MFA) adds a rotating authenticator app code to your Unraid account sign-in.
+
+The Account app currently supports authenticator app codes, also called TOTP or software-token MFA.
+
+## Before you start
+
+- Go to [account.unraid.net](https://account.unraid.net) and sign in to your Unraid account.
+- Install an authenticator app that can scan a QR code or accept a setup URL.
+- Keep your authenticator app available while changing MFA settings.
+
+## Enable MFA
+
+1. Open the Unraid Account app.
+2. Open **Account Settings**, then select the **MFA** tab.
+3. Click **Enable MFA**.
+4. Scan the QR code with your authenticator app. If you cannot scan the QR code, copy the setup URL into your authenticator app.
+5. Enter the 6-digit code from your authenticator app.
+6. Wait for the Account app to verify the code and show MFA as enabled.
+
+After MFA is enabled, use your authenticator app code the next time you sign in.
+
+## Disable MFA
+
+1. Open the Unraid Account app.
+2. Open **Account Settings**, then select the **MFA** tab.
+3. Click **Disable MFA**.
+4. Enter the current 6-digit code from your authenticator app.
+5. Confirm the change.
+6. Wait for the Account app to show MFA as disabled.
+
+After MFA is disabled, the Account app no longer asks for an authenticator app code during sign-in.
+
+## Troubleshooting
+
+- If setup fails, start again from the **MFA** tab in **Account Settings** and scan the new QR code.
+- If a code is rejected, wait for the next code in your authenticator app and try again.
+- If you no longer have access to your authenticator app, contact support for help recovering access to your account.