Use yarn workspace

[macabeus]

As long I understand, we have two projects inside of this repository:

• frontend, to what the user will see and interact
• nizkctf, that is the backend of the application

We could use some approaches, such as yarn workspaces to share the packages and run just one time the yarn command.

Also if we'll share some code between frontend and backend, the workspace will help us on this task.

[LorhanSohaky]

Thanks for the tip. Currently the js backend project is not being developed, but when we go back to development, we will fix the package sharing.