message: Change git token to git extraHeader
diff: mkdir __update_docs_temp
  cd ./__update_docs_temp
  mkdir service
  -git clone https://$GTTOKEN@github.com/surveyjs/service
  +REPO_URL="https://github.com/surveyjs/service"
  +git -c http.$REPO_URL.extraHeader="Authorization: Basic $GITAUTH" \
  + clone $REPO_URL
  mv ../docs/images .
  cp -a ../docs/. ./service/surveyjs.io/App_Data/Docs
  mv ./images ../docs
  