[DOCS] Adds Elastic Contributor Program link (#83561) (#84241)

Co-authored-by: Kaarina Tungseth <kaarina.tungseth@elastic.co>

docs/developer/contributing/index.asciidoc

@@ -2,7 +2,7 @@
 == Contributing
 
 Whether you want to fix a bug, implement a feature, or add some other improvements or apis, the following sections will 
-guide you on the process.
+guide you on the process. After committing your code, check out the link:https://www.elastic.co/community/contributor[Elastic Contributor Program] where you can earn points and rewards for your contributions.
 
 Read <<development-getting-started>> to get your environment up and running, then read <<development-best-practices>>.