block robots

BLOCK ROBOTS of a repository

Create a new branch, named NEWBRANCH

git checkout -b NEWBRANCH
git push -u origin NEWBRANCH

Change the default branch to NEWBRANCH, See settings of your repository.

Remove the master branch

git branch -d master
git push origin :master

THIS WILL NOT WORK WITH GITHUB-BASED WEBPAGES USING USERNAME.GITHUB.IO

Reference