Deprecate the app

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

README.md

@@ -1,4 +1,6 @@
-# U2F second factor provider for Nextcloud
+# ⚠️ Deprecated ⚠️ U2F second factor provider for Nextcloud
+
+⚠️ The U2F standard has been deprecated and therefore this app will be discontinued. The [Two-Factor WebAuthn](https://apps.nextcloud.com/apps/twofactor_webauthn) app can be used as a replacement. [Here](https://github.com/nextcloud/twofactor_webauthn#migration-from-two-factor-u2f) you can find migration instructions.
 
 ![Downloads](https://img.shields.io/github/downloads/nextcloud/twofactor_u2f/total.svg)
 ![Scrutinizer Code Quality](https://scrutinizer-ci.com/g/nextcloud/twofactor_u2f/badges/quality-score.png?b=master)

appinfo/info.xml

@@ -1,9 +1,9 @@
 <?xml version="1.0"?>
 <info xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://apps.nextcloud.com/schema/apps/info.xsd">
 	<id>twofactor_u2f</id>
-	<name>Two-Factor U2F</name>
-	<summary>U2F two-factor provider</summary>
-	<description>A two-factor provider for U2F devices</description>
+	<name>⚠️ Deprecated ⚠️ Two-Factor U2F</name>
+	<summary>U2F two-factor provider (deprecated)</summary>
+	<description>Deprecated two-factor provider for U2F devices. The Two-Factor WebAuthn provider replaces this app.</description>
 	<version>6.4.0-alpha.1</version>
 	<licence>agpl</licence>
 	<author>Christoph Wurst</author>