Note on git blame in GitLab in tips lecture

tips/tips.tex

@@ -107,6 +107,9 @@
a4394d28 (bow 2014-06 ...) Second version.
\end{lstlisting}
\bigskip
+  \pause
+  Similar functionality is also available in GitLab by clicking on the {\em
+    blame} button when viewing a file.
\end{frame}