Include Changelog

spec/spec.tex

@@ -1513,6 +1513,10 @@ is functional congruence, and \proofRule{sko_forall} works like
 4. &  & \ctxsep &  $(\neg\forall x.\,(p\,x))≈ \neg (p\,(\varepsilon x.\,\neg (p\,x)))$ &  $(\proofRule{cong}\, 3)$ \\
 \end{AletheS}
 
+\section{Changelog}
+\label{sec:changelog}
+\input{changelog}
+
 \section{Bibliography}
 \bibliographystyle{plain}
 \bibliography{publications}