When cloning this repository include the --recursive flag. I.e.
git clone https://github.com/jannikbuschke/formik-antd-playground --recursive
In the root folder execute
npm install
npm run bootstrap
npm run watch
npm run start (in a second terminal)
Now edits in the module formik-antd and in app should live update on localhost:3000.