docs: add notice to bottom of templated README.mds (#96)

Author: JoshuaKGoldberg

script/setup.js

@@ -119,6 +119,15 @@ try {
 			"./package.json",
 		],
 		[/## Explainer.*## Usage/s, `## Usage`, "./README.md"],
+		[
+			"<!-- ALL-CONTRIBUTORS-LIST:END -->",
+			`<!-- ALL-CONTRIBUTORS-LIST:END -->
+
+<!-- You can remove this notice if you don't want it 🙂 no worries! -->
+
+> 💙 This package is based on [@JoshuaKGoldberg](https://github.com/JoshuaKGoldberg)'s [template-typescript-node-package](https://github.com/JoshuaKGoldberg/template-typescript-node-package).`,
+			"./README.md",
+		],
 	]) {
 		await replace({ files, from, to });
 	}