nsupdate - self hosted DynDNS provider (#1108)

* nsupdate - self hosted DynDNS provider

* fix nsupdate entry

* fix spacing/newlines

README.md

@@ -503,6 +503,7 @@ _Recipe management_
 
 See https://github.com/n1trux/awesome-sysadmin#dns
 
+  * [nsupdate.info](https://www.nsupdate.info/) - nsupdate.info is a dynamic DNS service. ([Demo](https://www.nsupdate.info/account/register/), [Source Code](https://github.com/nsupdate-info/nsupdate.info)) `BSD` `Python`
 
 ## Document Archiving