1. Run setup.sh
It will download all the required sources and apply the patches

Next you can go to grapesjs-preset-webpage: cd grapesjs-preset-webpage
and start the application: npm start

2. If you want to change promoclock plugin 
go to grapesjs-component-promoclock: cd grapesjs-component-promoclock
run: npm i
make changes in src dir
run: npm run buld 
the component is generated in dist dir
go back to grapesjs-preset-webpage and restart the server (npm start)

3. if you want to apply new grapesjs to mautic 
go to grapesjs-preset-webpage
run: npm run build
in dist dir will  be located new grapsejs

place content of dist dir in on mautic_data volume: /var/lib/docker/volumes/mautic_data/_data/plugins/GrapesJsBuilderBundle/Assets/library/js/