add section about peepeth

thesis/content/03-related-work.tex

@@ -21,6 +21,7 @@ This chapter gives a comprehensive overview about different projects trying to p
 
 \section{Peepeth}
 \label{sec:peepeth}
+\input{content/03-related-work/peepeth}
 
 \section{LifeSocial.KOM}
 \label{sec:lifesocial}