Adress Yaroslav's comments on initial page layout

[mblomdahl]

Address PR #34 review comments from @Dykyi:

• [x] Have different views in a screens/ structure
• [x] Do not copy inline styling everywhere (share instead)
• [x] Make components more light-weight
• [x] Have shared types in a types/ color
• [x] Declare colors somewhere where they can be shared
• [x] Use "layouts" in the App.tsx
• [x] Add a utils/ for things like sizing functions
• [x] Use hooks for reusing

[ar9708]

Resolved in #51