Add a note about the Udemy license

docs/index.md

@@ -13,7 +13,7 @@ A number of links to more specific CERN trainings will be given when necessary.
 
 * This guide will not mention unsupported distributions. It will focus on the supported versions at CERN: i.e. _CERN CentOS 7, Alma and RHEL_.
 
-* This guide is not an introduction to Linux. It is focused of CERN-related features (packages, repositories, filesystems, etc.). If you are new to Linux, you might want to check some of the courses available through the LMS course [UDEMY for CERN](https://lms.cern.ch/ekp/servlet/ekp?PX=N&TEACHREVIEW=N&CID=EKP000044151&TX=FORMAT1&LANGUAGE_TAG=en&DECORATEPAGE=N), such as:
+* This guide is not an introduction to Linux. It is focused of CERN-related features (packages, repositories, filesystems, etc.). If you are new to Linux, you might want to check some of the courses available through the LMS course UDEMY for CERN, such as:
 
     For absolute beginners:
 
@@ -24,6 +24,7 @@ A number of links to more specific CERN trainings will be given when necessary.
     * [CentOS 7 Linux Server: Alternative to Red Hat Enterprise](https://cern.udemy.com/course/centos-7-linux-server-administration-alternative-to-red-hat-enterprise/)
     * Linux Academy Red Hat Certified Systems Administrator Prep ([SA1](https://cern.udemy.com/course/redhat-linux-administration-l/) and [SA2](https://cern.udemy.com/course/linux-administration-ll/))
 
+* Please note that UDEMY licence is needed to take the courses. It can be found in LMS and has a cost.
 
 * This guide will not explain how to manage machines or services in the datacentre, please check:
     * <https://cern.ch/clouddocs/>