Setup

First of all, you need to have a gh-pages. If you don't have, create:

git branch gh-pages

This makes a branch based on the master HEAD. It would be okay but the files and the git history of master branch are not meaningful on gh-pages branch. Using an --orphan branch, you can initialize gh-pages in a clean way.

git checkout --orphan gh-pages
git reset --hard
git commit --allow-empty -m "Init gh-pages branch"
git checkout master

Then, mount the branch as a subdirectory using git worktree:

git worktree add dist gh-pages

If you didn't ignore the dist folder, ignore it so that you don't add generated files accidentally in your master branch commits.

echo "dist/" >> .gitignore

Deploy

Every time you build the static bundle, generated files are in dist directory. Since dist folder is now gh-pages branch, you can deploy it directly by just creating a commit and pushing it.

cd dist
git add --all
git commit -m "Deploy on gh-pages updated"
git push origin gh-pages

This way nothing was added to the master branch history, keeping it clean.