docs: add npmx-weekly to README.md (#1142)

Author: trueberryless

README.md

@@ -157,6 +157,7 @@ We welcome contributions – please do feel free to explore the project and
 - [npkg.lorypelli.dev](https://npkg.lorypelli.dev/) – An alternative frontend to npm made with as little client-side JavaScript as possible
 - [vscode-npmx](https://github.com/npmx-dev/vscode-npmx) – VSCode extension for npmx
 - [nxjt](https://nxjt.netlify.app) – npmx Jump To: Quickly navigate to npmx common webpages.
+- [npmx-weekly](https://npmx-weekly.trueberryless.org/) – A weekly newsletter for the npmx ecosystem. Add your own content via suggestions in the weekly PR on [GitHub](https://github.com/trueberryless-org/npmx-weekly/pulls?q=is%3Aopen+is%3Apr+label%3A%22%F0%9F%95%94+weekly+post%22).
 - [npmx-digest](https://npmx-digest.trueberryless.org/) – An automated news aggregation website that summarizes npmx activity from GitHub and Bluesky every 8 hours.
 
 If you're building something cool, let us know! 🙏