fix: declare repository URL in package.json

npm's provenance verification (attached automatically by OIDC trusted
publishing) rejects the publish with E422 unless package.json's
repository.url matches the repo the attestation was built from.

Author: MattJackson

package.json

@@ -3,6 +3,10 @@
   "version": "0.2.0",
   "description": "TypeScript SDK for the Busbar admin API (generated from the typed OpenAPI 3.1 schema).",
   "license": "Apache-2.0",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/GetBusbar/busbar-js.git"
+  },
   "author": "Busbar, Inc.",
   "type": "module",
   "main": "./src/index.ts",