create site pulling script

pull-site.sh

+#!/bin/bash
+
+if [ -d site/ ]; then
+  echo "Delete the site/ directory before pulling site data."
+  exit 1
+fi
+
+curl -LO https://github.com/uabrc/uabrc.github.io/archive/refs/heads/gh-pages.tar.gz
+mkdir -p site/
+tar -xvf gh-pages.tar.gz -C site/
+mv site/uabrc.github.io-gh-pages/{.[!.]*,*} site/
+rmdir site/uabrc.github.io-gh-pages
+rm gh-pages.tar.gz