fix: make typescript peer optional and relax range (>=5.0.0)

[tnayuki]

Fixes #7.

Problem

typescript is declared as a required peer dependency pinned to ^6.0.2. Any consumer not on TypeScript 6.x fails to install:

npm error ERESOLVE unable to resolve dependency tree
npm error peer typescript@"^6.0.2" from electron-webauthn@1.3.1
npm error Found: typescript@4.5.5

TypeScript is needed neither at install nor at runtime — the package ships compiled JS (dist/index.js), and the bundled .d.ts uses only basic declaration syntax (verified to type-check under TS 4.5 with skipLibCheck). The ^6.0.2 peer effectively tracks the version TS was built with (history: none → ^5 → ^6.0.2) rather than a real minimum.

Change

- "peerDependencies": { "typescript": "^6.0.2" }
+ "peerDependencies": { "typescript": ">=5.0.0" },
+ "peerDependenciesMeta": { "typescript": { "optional": true } }

• optional: true stops the peer from breaking npm install for consumers who don't have (or don't need) TypeScript — this is the key fix.
• >=5.0.0 relaxes the caret pin to a lower bound, so newer TS releases keep satisfying it without further bumps.

This matches common practice for type-shipping packages: many declare no typescript peer at all (zod, type-fest, drizzle-orm, @trpc/server), and those that do mark it optional with a >= bound (valibot >=5 optional, ts-essentials >=4.5.0 optional).

No runtime or API changes.