fix: broken url in minimize-http-requests.md (#5324)

* fix: broken url in minimize-http-requests.md

existing URL points to unavailable resources. I provided a more reliable URL with very good insight to the topic.
Updated description to include a little more context providing enough heads up before visiting the URL to read the details

* Update src/data/best-practices/frontend-performance/content/minimize-http-requests.md

---------

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

src/data/best-practices/frontend-performance/content/minimize-http-requests.md

@@ -1,6 +1,6 @@
 # Minimize HTTP Requests
 
 > Always ensure that every file requested are essential for your website or application.
+> Combine files, Enable caching, use a content delivery network and Eliminate unnecessary resources 
 
-- [Combine external CSS](https://varvy.com/pagespeed/combine-external-css.html)
-- [Combine external JavaScript](https://varvy.com/pagespeed/combine-external-javascript.html)
+- [Best Strategies for Minimizing HTTP Requests](https://www.linkedin.com/advice/3/what-best-strategies-minimizing-http-requests-skills-e-commerce)