Clean up web code

[ASleepyCat]

Some preliminary clean up to better understand how Svelte's reactivity and data binding works.

Some notes:

• Binding on class properties works
• Reactivity with objects is a bit buggy in Svelte 4 e.g. the double update issue when loading the config. Apparently this is fixed in Svelte 5 with their new runes system

Changes:

• Remove README.md and lib/index.ts in beef-config
• Update eslint rule so that using _ for an unused variable doesn't show a linting error in .ts files
• Separate various parts of web code into individual components
• Improve colour picker code to use Svelte reactivity instead
• Make Switch centred with label text
• Rename disable_led to disable_leds