use files field instead of .npmignore

Author: aholachek

.npmignore

@@ -5,8 +5,11 @@
   "main": "dist/main.js",
   "module": "dist/main.module.js",
   "types": "dist/index.d.ts",
-  "description": "Smooth, easy transitions for CSS grid",
+  "description": "Buttery smooth, easy transitions for CSS grid",
   "homepage": "https://github.com/aholachek/animate-css-grid",
+   "files": [
+    "/dist"
+  ],
   "keywords": [
     "css",
     "grid",