logo: added url to project

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

README.md

@@ -1,5 +1,7 @@
 <p align="center">
-  <img src="https://github.com/trimstray/the-book-of-secret-knowledge/blob/master/static/img/the-book-of-secret-knowledge-preview.png" alt="Master">
+  <a href="https://github.com/trimstray/the-book-of-secret-knowledge">
+    <img src="https://github.com/trimstray/the-book-of-secret-knowledge/blob/master/static/img/the-book-of-secret-knowledge-preview.png" alt="Master">
+  </a>
 </p>
 
 <p align="center">"<i>Knowledge is powerful, be careful how you use it!</i>"</p>