Add Squarespace Engineering article on native HTML video/audio lazy loading (#237)

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Co-authored-by: davidsonfellipe <381179+davidsonfellipe@users.noreply.github.com>

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content/ARTICLES.md

@@ -35,6 +35,7 @@ path: /articles/
 - [Third Parties and Single Points of Failure](https://paulcalvano.com/2025-12-29-third-parties-and-single-points-of-failure/) - by Paul Calvano
 - [Serving Static Content with Cloud Storage? Don't Forget the CDN!](https://paulcalvano.com/2026-02-09-serving-static-content-with-cloud-storage-dont-forget-the-cdn/) - by Paul Calvano
 - [Introducing Waterfall Tools](https://blog.patrickmeenan.com/2026/04/12/introducing-waterfall-tools/) - by Patrick Meenan
+- [How to use standard HTML video and audio lazy loading on the web today](https://engineering.squarespace.com/blog/2026/how-to-use-standard-html-video-and-audio-lazy-loading-on-the-web-today) - by Squarespace Engineering
 
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