yarn everything first!
then you have these commands:
yarn web:dev - development version of the webapp, at http://localhost:8080 if run before/without electron command
yarn electron:dev - development version of the electron app
these two can be run side by side, or you can just run
yarn all:dev - runs both of the above commands in parallel, with web at http://localhost:8081
If you are looking for a starter kit, there are many excellent electron boilerplates that could be customized for this purpose. With electron, you want to have your development and release toolchain down pat. Don't sacrafice having that just because your boilerplate doesn't have this one specific feature (building to a web target).
Next episode I will recreate this using webpack-electron, and show some patterns you can use for conditionally loading electron-renderer specific dependencies.