whois: add page (#3552)

pages/common/whois.md

@@ -0,0 +1,16 @@
+# whois
+
+> Commandline client for the WHOIS (RFC 3912) protocol.
+> More information: <https://github.com/rfc1036/whois>.
+
+- Get information about a domain name:
+
+`whois {{example.com}}`
+
+- Get information about an IP address:
+
+`whois {{8.8.8.8}}`
+
+- Get abuse contact for an IP address:
+
+`whois -b {{8.8.8.8}}`