Revise Contributor License Agreement instructions

Updated CLA instructions and added reference to FOSS guidelines.

Author: marianoao

CONTRIBUTING.md

@@ -12,8 +12,9 @@ this project.
 
 ## Prerequisites
 
-- Before starting to contribute to the code, you must first sign the
-[Contributor License Agreement (CLA)](https://forms.office.com/pages/responsepage.aspx?id=tr3oyHyO1UG8QTf_88M7dUcieUMXXWlMt4DQ48jCBMZUM1FCMUFZNFRPWVpSV1hUREIzVzlSN0E4Qy4u).
+- Before starting to contribute to the code, you must first sign the Contributor License Agreement (CLA). Detailed
+  instructions on how to proceed can be found in the
+  [FOSS contributing guidelines](https://github.com/InditexTech/foss/blob/main/CONTRIBUTING.md).
 
 ## Contribute Guidelines