Added copyright information for the used icons8 icons to the notice file

NOTICE

@@ -11,3 +11,15 @@ Top Shelf Image
 ---------------
 The Top Shelf image contains Public Domain artwork by Image Catalog under the Public Domain Dedication (CC0) license.
 URL: https://flic.kr/p/z8eDKH
+
+Icons
+-----
+Several icons in this application and in this license documentation have been created by Icons8 (https://icons8.com) under 
+the Creative Commons Attribution-NoDerivs 3.0 Unported license. Take a look at the icons they have created, they're great!
+Info icon               : https://icons8.com/web-app/42236/Info
+Info filled icon        : https://icons8.com/web-app/2800/Info-Filled
+Settings icon           : https://icons8.com/web-app/364/Settings
+Closed captioning icon  : https://icons8.com/web-app/14823/closed-captioning
+Not hearing icon        : https://icons8.com/web-app/7534/not-hearing
+SSL icon                : https://icons8.com/web-app/40035/Security-SSL
+Security checked icon   : https://icons8.com/web-app/42371/security-checked