Add session type to `Window Manager` entry

[Tobilike]

I add a check for the Display-Server-Protokoll

Description

The system checks whether a Display Manager is available; if so, it is displayed under Window Manager. A system variable is checked, if this cannot be found, nothing happens.

Reason and / or context

It is useful because there are 2 of them and it is not clear which is used.

How has this been tested ?

On 2 Systems

Types of changes :

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] Typo / style fix (non-breaking change which improves readability)
• [?] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist :

• [ ] [IF NEEDED] I have updated the README.md file accordingly ;
• [ ] [IF NEEDED] I have updated the test cases (which pass) accordingly ;
• [ ] [IF BREAKING] This pull request targets next Archey version branch ;
• [X] My changes looks good ;
• [X] I agree that my code may be modified in the future ;
• [X] My code follows the code style of this project (PEP8).

[ingrinder]

Hi again!

As in #141, do you think you would be able to rebase this onto master with just the relevant commits? If not, we can do it for you, though note it would require a force push which will clobber your local copy of the branch (particularly any changes not pushed).

[HorlogeSkynet]

Closing here in favor of #145.