add contributor count from Community page

Author: nshaffer

FortranCon2021-stdlib/stdlib-talk.tex

@@ -190,6 +190,7 @@
   \begin{itemize}
   \item From 16 committors to 34, including our 2 GSoC students
   \item Over 100 new Issues: bugs, workflow improvements, feature proposals
+  \item From 52 to 97 contributors (commits, discussion, reviews)
   \end{itemize}
 
   \begin{block}{Commits to stdlib since FortranCon 2020}