Create monorepo

[SuperVK]

Problem: frontend-common contains part of our codebase, but actually developing this code is almost impossible because it lives in a repository. For example stores, theming, fonts should probably live in the common, but right now is half in this repository and half in the frontend-common, depending on what people feel like.

Solution: Move everything to a monorepo.
This would create 3/(4) packages:

• pos
• frontend (this repository but needs a better name, because the whole monorepo is the frontend)
• common
• (theming, could also be part of the common)

Steps:

• Rename https://github.com/GEWIS/sudosos-frontend-old
• Rename sudosos-frontend and archive
• Rename this repo to sudosos-frontend
• Move everything into this repo
• Archive the common and pos to preserve commit history
• Create a top level package.json
• Fix the actions
• Move all the stores to the common
• Move the theme to a central place

[SuperVK]

Closed in favor of #189