add TypeScript defintions

index.d.json.ts

@@ -0,0 +1,14 @@
+export interface Tag2Link {
+  /** OSM tag key */
+  key: `Key:${string}`;
+  /** URL template or formatter URL: replace `$1` with the tag value */
+  url: string;
+  /** Source of this formatter URL */
+  source: `${'wikidata' | 'osm'}:P${number}`;
+  /** Rank or relative importance of this formatter URL */
+  rank: 'preferred' | 'normal' | 'deprecated';
+}
+
+declare const exports: Tag2Link[];
+
+export default exports;

package.json

@@ -10,6 +10,7 @@
     "url-template"
   ],
   "main": "index.json",
+  "types": "index.d.json.ts",
   "scripts": {
     "build": "npx ts-node build.ts"
   },