[ci skip] correct pre-script for doc (again)

docs/pre_script.sh

@@ -14,3 +14,10 @@ DIR=$HOME/limbo_benchmarks
 BENCHMARKS=$DIR/`ls $DIR|sort -n|head -n 1`
 cp $BENCHMARKS/bo_benchmarks.rst docs/bo_benchmarks.rst
 cp -r $BENCHMARKS/fig_benchmarks docs
+
+echo "getting the latest regression benchmark result (needs to be in $HOME/limbo_reg_benchmarks)"
+DIR=$HOME/limbo_ref_benchmarks
+BENCHMARKS=$DIR/`ls $DIR|sort -n|head -n 1`
+cp $BENCHMARKS/regression_benchmarks.rst docs/reg_benchmarks.rst
+cp -r $BENCHMARKS/regression_benchmarks_figs docs
+