chore: add version to package.json

Related #6

package.json

@@ -1,6 +1,7 @@
 {
   "main": "dist/project-x.js",
   "name": "project-x",
+  "version": "0.2.0",
   "scripts": {
     "test": "jest",
     "test:debug": "node --inspect node_modules/.bin/jest --runInBand",