add license info to about

_data/extra.yml

@@ -1,2 +1,2 @@
 list:
-  footer_bio: pwrd by jekyll, html5 and css3. written in vim. 
+  footer_bio: pwrd by jekyll, written in vim, no js

about.html

@@ -17,7 +17,9 @@ Besides studying, I'm an educator for network- and system engineering at a local
 My first language is German, but I prefer English for general communication.
 </p>
 <p>
+All content on my page is <a href="https://www.gnu.org/licenses/gpl-3.0.html">GPLv3</a> unless noted otherwise.
+</p>
+<p>
 If you have any questions, shoot me a mail! The server's <code>koneko.at</code>, the correct mailbox is <code>neko</code>.
 </p>
-
 <!-- Look, I know trinitrons are colour crts, but I really like the frame. Please don't lynch me. -->