[meta] add npmignore

Author: ljharb

.gitignore

@@ -7,3 +7,5 @@ coverage/
 npm-shrinkwrap.json
 package-lock.json
 yarn.lock
+
+.npmignore

package.json

@@ -5,6 +5,7 @@
 	"main": "index.js",
 	"sideEffects": false,
 	"scripts": {
+		"prepack": "npmignore --auto --commentLines=autogenerated",
 		"lint": "eslint --ext=js,mjs .",
 		"pretest": "npm run lint",
 		"tests-only": "nyc tape 'test/**/*'",
@@ -29,9 +30,16 @@
 		"available-typed-arrays": "^1.0.7",
 		"eslint": "=8.8.0",
 		"for-each": "^0.3.5",
+		"npmignore": "^0.3.1",
 		"nyc": "^10.3.2",
 		"tape": "^5.9.0"
 	},
+	"publishConfig": {
+		"ignore": [
+			".github/workflows",
+			"test"
+		]
+	},
 	"engines": {
 		"node": ">= 0.4"
 	}