Enable recommended ESlint rules

The main one we're interested in is "no-mixed-spaces-and-tabs"
(https://eslint.org/docs/latest/rules/no-mixed-spaces-and-tabs).

Author: haguenau

package.json

@@ -5,6 +5,9 @@
     "test": "jest",
     "all": "npm run lint && npm run prepare && npm run test"
   },
+  "eslintConfig": {
+    "extends": "eslint:recommended"
+  },
   "dependencies": {
     "@actions/core": "^1.10.0",
     "avro-js": "^1.11.1"