feat: add TypeScript types (#28)

lexer.d.ts

@@ -0,0 +1,9 @@
+interface Exports {
+  exports: string[];
+  reexports: string[];
+}
+
+export declare function parse(source: string, name?: string): Exports;
+export declare function init(): Promise<void>;
+
+export {};

package.json

@@ -7,6 +7,7 @@
     "import": "./dist/lexer.mjs",
     "default": "./lexer.js"
   },
+  "types": "lexer.d.ts",
   "scripts": {
     "test-js": "mocha -b -u tdd test/*.js",
     "test-wasm": "WASM=1 mocha -b -u tdd test/*.js",
@@ -28,7 +29,8 @@
     "terser": "^4.1.4"
   },
   "files": [
-    "dist"
+    "dist",
+    "lexer.d.ts"
   ],
   "repository": {
     "type": "git",