- Update `overrides.ts` imports

- Add missing comment and `;` in `eslint.config.js`

- `field/pokemon.ts`:

Rename `generateVariant` to `generateShinyVariant`

Mark some functions as `public`/etc

Update various tsdocs/comments, add tsdocs to `isOfType`

Turn an unreadable 450+ character line into a
readable block of code

- `utils.ts`:

Remove unused function `randSeedEasedWeightedItem`

Mark `IntegerHolder` and `FixedInt` as deprecated

Update some tsdocs/comments

Rename `getTarget` to `getFirstTarget` for clarity

Convert namespace import to named imports

Add `public`/etc to methods