add image and fix warning label for RustDesk

Signed-off-by: Stephen L. <lrq3000@gmail.com>

_includes/sections/productivity-tools.html

@@ -86,7 +86,7 @@
   image="/assets/img/png/3rd-party/rustdesk.png"
   image-dark="/assets/img/png/3rd-party/rustdesk.png"
   description="<strong>RustDesk</strong> is an easy to use end-to-end encrypted remote desktop software with no network configuration required, simply share the randomly generated ID and password to get assisted, no registration needed. The <a href=//github.com/rustdesk/rustdesk/issues/63>connection is end-to-end encrypted</a>, so that content is never decrypted by the server."
-  labels="color==warning::text==Warning::tooltip==Although the software works by default using a free public instance, self-hosting is advised for more security."
+  labels="color==warning::icon==fas fa-exclamation-triangle::tooltip==Although the software works by default using a free public instance, self-hosting is advised for more security."
   website="https://rustdesk.com/"
   github="https://github.com/rustdesk/rustdesk"
   windows="https://github.com/rustdesk/rustdesk/releases"