add commit and push to generate-markdown task, see https://github.com/phetsims/sherpa/issues/22
add commit and push to generate-markdown task, see https://github.com/phetsims/sherpa/issues/22

concord-consortium/chipper,concord-consortium/chipper,concord-consortium/chipper,phetsims/chipper,phetsims/chipper,concord-consortium/chipper,phetsims/chipper