#24 - added 'securitynewsletter.co'

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

README.md

@@ -578,6 +578,7 @@ Linux Security Expert</b></a> - trainings, howtos, checklists, security tools an
 ##### :black_small_square: Security
 
 <p>
+&nbsp;&nbsp;:small_orange_diamond: <a href="https://securitynewsletter.co/"><b>Security Newsletter</b></a> - security news as a weekly digest (email notifications).<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://security.googleblog.com/"><b>Google Online Security Blog</b></a> - the latest news and insights from Google on security and safety on the Internet.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://blog.qualys.com/"><b>Qualys Blog</b></a> - expert network security guidance and news.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://www.darkreading.com/"><b>DARKReading</b></a> - connecting the Information Security Community.<br>