Documentation for shared library

Extending with Shared Libraries mentions that global variables can be documented in .txt files representing those variables, and this documentation appears in the Global Variable Reference window.

So I have created my variable msbuild.groovy and the documentation at msbuild.txt. Put them into /vars folder of my shared library. Ran the associated job successfully, however the documentation in the Jenkins UI is not present.

Does this still supposed to work, or not anymore?

Never mind. Was looking at the job level, but the documentation is available only at branch level in multibranch pipeline job.