added a new website (#10053)

added a new website to showcase

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Author: prasadseth

docs/sites.yml

@@ -3507,3 +3507,11 @@
   categories:
     - Marketing
     - IOT
+- title: freeCodeCamp curriculum
+  main_url: "https://learn.freecodecamp.org"
+  url: "https://learn.freecodecamp.org"
+  featured: false
+  description: Learn to code with free online courses, programming projects, and interview preparation for developer jobs.
+  categories:
+    - Web Development
+    - Learning