Add eslint configuration and scripts

.eslintrc.json

@@ -0,0 +1,16 @@
+{
+    "env": {
+      "commonjs": true,
+      "es2021": true,
+      "node": true,
+      "jest": true
+    },
+    "plugins": ["github"],
+    "extends": ["eslint:recommended", "prettier", "plugin:github/internal"],
+    "parserOptions": {
+      "ecmaVersion": 12
+    },
+    "rules": {},
+    "ignorePatterns": ["/dist/**/*.js", "/src/fixtures/", "/src/blank-configurations/"]
+  }
+

package.json

@@ -7,7 +7,9 @@
   "scripts": {
     "format": "prettier --write 'src/**/*.js'",
     "format:check": "prettier --check 'src/**/*.js'",
-    "prepare": "npm run format && ncc build src/index.js -o dist --source-map --license licenses.txt",
+    "lint": "DEBUG=eslint:cli-engine eslint --fix .",
+    "lint:check": "DEBUG=eslint:cli-engine eslint .",
+    "prepare": "npm run format && npm run lint && ncc build src/index.js -o dist --source-map --license licenses.txt",
     "test": "jest"
   },
   "repository": {