add pdf definition

config @ b99f1946

-Subproject commit 5073aca27278d793d18a887dd4d861ff7de54126
+Subproject commit b99f1946354023fe407246eccb9351058915141e

intro.tex

@@ -20,7 +20,8 @@
   \fi
   \item
   BIND has no house rules, and never will.
-  Everyone has complete access to the files so you can just change the rules, and re-print the pdf.
+  Everyone has complete access to the files so you can just change the rules, and re-print the \gls{pdf}.
+  \glsadd{pdf}
 \end{itemize}
 
 \subsection*{Context}