Add Domain Whois and DNS lookup

Hi,
Thanks for creating Sputnik, it is a really great extension. I use it everyday and it makes my work much easier.
I would like you to explore adding domain name whois and DNS lookup options.
I have been using these which you can check:
Whois:
https://autowhois.com
https://mxtoolbox.com/whois.aspx

DNS lookup:
https://nslookup.io (better)
https://dns.google