add project-specifc conf for the 'ack' search tool

See https://beyondgrep.com/ for details.

.ackrc

+# Configuration file for the 'ack' search utility
+# See https://beyondgrep.com/ for details.
+
+# Ignore misc files generated by the build process
+--ignore-file=ext:glob,aux
\ No newline at end of file