Update tsconfig.json (#34)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: James-N-M

src/declarations.d.ts

@@ -2,7 +2,8 @@
   "composite": true,
   "extends": "../tsconfig.json",
   "compilerOptions": {
-    "baseUrl": "./"
+    "baseUrl": "./",
+    "lib": ["es6", "dom"]
   },
   "include": ["./"],
   "exclude": ["./fixtures"]