add 'OWASP Cheat Sheet Series'

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

README.md

@@ -737,6 +737,7 @@ performance of any of your sites from across the globe.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://github.com/OWASP/ASVS/tree/master/4.0"><b>OWASP ASVS 4.0</b></a> - is a list of application security requirements or tests.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://www.owasp.org/index.php/OWASP_Testing_Project"><b>OWASP Testing Guide v4</b></a> - includes a "best practice" penetration testing framework.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://github.com/OWASP/DevGuide"><b>OWASP Dev Guide</b></a> - this is the development version of the OWASP Developer Guide.<br>
+&nbsp;&nbsp;:small_orange_diamond: <a href="https://cheatsheetseries.owasp.org/"><b>OWASP Cheat Sheet Series</b></a> - is a collection of high value information on specific application security topics.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://infosec.mozilla.org/guidelines/web_security.html"><b>Mozilla Web Security</b></a> - help operational teams with creating secure web applications.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://enable-cors.org/index.html"><b>Enable CORS</b></a> - enable cross-origin resource sharing.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://appsecwiki.com/#/"><b>Application Security Wiki</b></a> - is an initiative to provide all application security related resources at one place.<br>