Restore README.md logo image lost during webp migration (73d6ed0) (#545)

* fix(img): replace icon256.png with logo-full.svg in README

* fix(README): add alt attribute to NoScript logo image

Author: KhaledSaeed18

README.md

@@ -15,7 +15,8 @@ SPDX-License-Identifier: GPL-3.0-or-later
 <br>
 
 [<img
-    src = 'src/img/icon256.png'
+    src = 'src/img/logo-full.svg'
+    alt = 'NoScript Logo'
     width = 120
 />][Website]