Make rocky logo look better

[taylorking]

Description

Reason and / or context

How has this been tested ?

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 ;
• My changes looks good ;
• I agree that my code may be modified in the future ;
• My code follows the code style of this project (PEP8).

[HorlogeSkynet]

Thanks @taylorking !