[meta] use npmignore --auto instead of files to limit published files

Author: ljharb

.gitignore

@@ -23,5 +23,8 @@ sftp-config.json
 eslint-remote-tester-results
 
 # Only apps should have lockfiles
-yarn.lock
+npm-shrinkwrap≥json
 package-lock.json
+yarn.lock
+
+.npmignore

package.json

@@ -5,6 +5,7 @@
   "description": "React specific linting rules for ESLint",
   "main": "index.js",
   "scripts": {
+    "prepack": "npmignore --auto --commentLines=autogenerated",
     "lint": "eslint .",
     "postlint": "npm run type-check",
     "pretest": "npm run lint",
@@ -15,12 +16,6 @@
     "generate-list-of-rules": "md-magic --path README.md",
     "generate-list-of-rules:check": "npm run generate-list-of-rules && git diff --exit-code README.md"
   },
-  "files": [
-    "LICENSE",
-    "README.md",
-    "index.js",
-    "lib"
-  ],
   "repository": {
     "type": "git",
     "url": "https://github.com/jsx-eslint/eslint-plugin-react"
@@ -68,6 +63,7 @@
     "ls-engines": "^0.6.6",
     "markdown-magic": "^2.6.0",
     "mocha": "^5.2.0",
+    "npmignore": "^0.3.0",
     "sinon": "^7.5.0",
     "typescript": "^3.9.9",
     "typescript-eslint-parser": "^20.1.1"
@@ -85,9 +81,18 @@
     "react"
   ],
   "license": "MIT",
-  "greenkeeper": {
+  "publishConfig": {
     "ignore": [
-      "semver"
+      ".github/",
+      "!lib",
+      "docs/",
+      "test/",
+      "tests/",
+      "*.md",
+      "*.config.js",
+      ".eslintrc",
+      ".editorconfig",
+      "tsconfig.json"
     ]
   }
 }