chore: Limit files published

Author: rschristian

package.json

@@ -51,6 +51,12 @@
 	"license": "MIT",
 	"bugs": "https://github.com/preactjs/preact-custom-element/issues",
 	"homepage": "https://github.com/preactjs/preact-custom-element",
+	"files": [
+		"dist",
+		"LICENSE",
+		"package.json",
+		"README.md"
+	],
 	"peerDependencies": {
 		"preact": ">= 10.25.0 || >=11.0.0-0"
 	},