adding duckdns option (home-assistant#13410)

source/_docs/configuration/securing.markdown

@@ -15,7 +15,10 @@ Here's the summary of what you *must* do to secure your Home Assistant system:
 
 ## Remote Access
 
-If you want secure remote access, the easiest option is to use [Home Assistant cloud](/cloud/). Other options are to use [TLS/SSL](/docs/ecosystem/certificates/lets_encrypt/) to expose your instance to the internet, use a [VPN](https://pivpn.dev/), [Tor](/docs/ecosystem/tor/) or an [SSH tunnel](/blog/2017/11/02/secure-shell-tunnel/).
+If you want secure remote access, the easiest option is to use [Home Assistant cloud](/cloud/) by which you also [support](https://www.nabucasa.com/about) the founders of Home Assistant. 
+
+Other options are to use TLS/SSL via the add-ons [Duck DNS integrating Let's Encrypt](/integrations/duckdns/) or [Let’s Encrypt](/docs/ecosystem/certificates/lets_encrypt/). 
+To expose your instance to the internet, use a [VPN](https://pivpn.dev/), [Tor](/docs/ecosystem/tor/) or an [SSH tunnel](/blog/2017/11/02/secure-shell-tunnel/). Make sure to expose the used port in your router. 
 
 ### Extras for manual installations