Create an orphan gh-pages directory in master

create_gh-pages_branch.sh

#!/usr/bin/env bash
#
# Run this in a repo checked out from github

#create gh-pages branch
git checkout --orphan gh-pages
git reset
echo "My new site" >> index.html
git add index.html
git commit --allow-empty -m "Initial commit gh-pages"
git push --set-upstream origin gh-pages

#in master create a linked checkout to gh-pages
git checkout --force master
git worktree add _export gh-pages

#disable jekyll and add _export to gitignore
touch .nojekyll
echo "_export" >> .gitignore
git add .
git commit -am "preparing for _export in a git worktree"
git push