Move Shared State to Stores

[TomChamberlainUK]

Move Shared State to Stores

Move shared logic behind notes to Svelte stores to reduce complexity

Description

Root, mode, and highlighting of notes are things that are wrapped up in almost all components

This is starting to become a problem because as the project grows the code is becoming too interconnected

We need to take some time to modularise this shared state

Notes

• The docs for Svelte stores are available here

Done When

• [x] Root is moved to a store
• [x] Mode is moved to a store
• [x] Highlighted notes & chords moved to stores
• [x] Selected note moved to store
• [x] Guitar component consumes highlighted notes via store
• [x] Piano component consumes highlighted notes via store
• [ ] Circle of Fifths consumes highlighted chords — Shifting to #77