[meta] use npmignore

Author: ljharb

.gitignore

@@ -4,3 +4,5 @@ node_modules
 npm-shrinkwrap.json
 package-lock.json
 yarn.lock
+
+.npmignore

package.json

@@ -5,6 +5,7 @@
   "browser": "browser.js",
   "main": "index.js",
   "scripts": {
+    "prepack": "npmignore --auto --commentLines=autogenerated",
     "lint": "eslint --ext=js,mjs .",
     "pretest": "npm run lint",
     "test": "npm run tests-only",
@@ -41,8 +42,14 @@
     "@ljharb/eslint-config": "^21.1.1",
     "eslint": "=8.8.0",
     "hash-test-vectors": "^1.3.2",
+    "npmignore": "^0.3.1",
     "tape": "^5.9.0"
   },
+  "publishConfig": {
+    "ignore": [
+      ".github/workflows"
+    ]
+  },
   "engines": {
     "node": ">= 0.8"
   }