chore: lint all files by default and add --report-unused-disable-directives flag

Linting all by default, and later adding an `.eslintignore` if necessary, allows IDEs to avoid showing errors on intentionally ignored files.

Author: brettz9

package.json

@@ -19,7 +19,7 @@
   "scripts": {
     "precommit": "lint-staged --concurrent false",
     "test": "jest",
-    "lint": "eslint rules __tests__ index.js",
+    "lint": "eslint --report-unused-disable-directives .",
     "format": "prettier --write '**/*.js'"
   },
   "dependencies": {},