Support generating `oxlint.config.ts` (TypeScript config)

[rakleed]

Currently, oxlint-migrate generates only .oxlintrc.json when migrating from ESLint. However, oxlint now officially supports a TypeScript config file named oxlint.config.ts (see docs).

Could you add an option (e.g., --config-format ts or --typescript) to oxlint-migrate that generates an oxlint.config.ts file instead of .oxlintrc.json?