Add prepare script for git URL installs

Enables installing directly from GitHub without publishing to npm.
The prepare script builds the dist/ folder during yarn/npm install.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: Taz Singh

package.json

@@ -12,6 +12,7 @@
     "dev": "vitest watch",
     "test": "vitest --run",
     "build": "tsup ./src/workerSwr.ts --format esm,cjs --dts",
+    "prepare": "tsup ./src/workerSwr.ts --format esm,cjs --dts",
     "release": "pnpm build && pnpm test && pnpm publish --tag beta"
   },
   "exports": {