add 'dnsgrep' and 'rapid7 datasets'

- signed-off-by: trimstray <trimstray@gmail.com>

README.md

@@ -521,6 +521,7 @@ Only main chapters:
 &nbsp;&nbsp;:small_orange_diamond: <a href="http://xip.io/"><b>xip.io</b></a> - wildcard DNS for everyone.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://ceipam.eu/en/dnslookup.php"><b>dnslookup (ceipam)</b></a> - one of the best DNS propagation checker (and not only).<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://whatsmydns.com"><b>What's My DNS</b></a> - DNS propagation checking tool.<br>
+&nbsp;&nbsp;:small_orange_diamond: <a href="https://blog.erbbysam.com/index.php/2019/02/09/dnsgrep/"><b>DNSGrep</b></a> - quickly searching large DNS datasets.<br>
 
 </p>
 
@@ -633,6 +634,8 @@ performance of any of your sites from across the globe.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://searchcode.com/"><b>searchcode</b></a> - helping you find real world examples of functions, API's and libraries.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="http://www.insecam.org/"><b>Insecam</b></a> - the world biggest directory of online surveillance security cameras.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="http://index-of.es/"><b>index-of</b></a> - contains great stuff like: security, hacking, reverse engineering, cryptography, programming etc.<br>
+&nbsp;&nbsp;:small_orange_diamond: <a href="https://opendata.rapid7.com/"><b>Rapid7 Labs Open Data</b></a> - is a great resources of datasets from Project Sonar.<br>
+
 </p>
 
 ##### :black_small_square: Generators