User defined weather effects

[valentine195]

Allow for user-defined weather effects that the weather generation model will take into account.

This could be, e.g., "Arcane Storms".

Weather effects will need a few things:

1. A chance table
2. Corresponding description table
3. Corresponding icon table (optional)

[valentine195]

Possibility:

type WeatherEffectCadence = 
  | "Seasonal" //chance is interpolated between seasons
  | "Global" //chance is static

type WeatherEffectKind =
  | "Range" //e.g., temperature
  | "ChanceTable" //e.g., precipitation
  | "Chance" //e.g., storm?

These effects should also allow conditions to be set - e.g., cloud cover >= 5 OR wind === 10 (for a storm).

They should also be allowed an icon, lucide or otherwise.

Ideally, all current effects would be described this way.