Add Technitium DNS to DNS Section. (#3113)

README.md

@@ -704,6 +704,7 @@ _See also: [awesome-sysadmin/DNS](https://github.com/awesome-foss/awesome-sysadm
 - [Maza ad blocking](https://maza-ad-blocking.andros.dev/) - Local ad blocker. Like Pi-hole but local and using your operating system. ([Source Code](https://github.com/tanrax/maza-ad-blocking)) `Apache-2.0` `Bash`
 - [nsupdate.info](https://www.nsupdate.info/) - Dynamic DNS service. ([Demo](https://www.nsupdate.info/account/register/), [Source Code](https://github.com/nsupdate-info/nsupdate.info)) `BSD-3-Clause` `Python`
 - [SPF Toolbox](https://spftoolbox.com) - Application to look up DNS records such as SPF, MX, Whois, and more. ([Source Code](https://github.com/charlesabarnes/SPFtoolbox)) `MIT` `PHP`
+- [Technitium DNS Server](https://technitium.com/dns/) - An open source authoritative as well as recursive DNS server that can be used for self hosting a DNS server for privacy & security. ([Source Code](https://github.com/TechnitiumSoftware/DnsServer)) `GPL-3.0` `Docker/C#`
 
 
 ### Document Management