Github action jobs should also have a description

As job titles are better kept as short as possible due to UI display limitation, dependencies and the fact that they are part of the URLs, there is a need to have a description field for jobs that should be used to describe the purpose of the job.

Ideally description field should be displayed as tooltip (html title element) where job names are displayed in the web page. When a user would hover a job name, they should be able to read the extra text that explains their purpose/goal.