Add fastfetch

[nnyyxxxx]

Merge #335 before this so it has synergy, as the current state of mybash without #335 will still attempt to implement fastfetch

Merge #409 before merging this, it includes little refactor regarding configs.

Review the other setup-scripts in #409 before deciding && compare them, this one has identical functionality to them.

Type of Change

• [x] New feature

Testing

Works as expected.

Issue related to PR

• Resolves #400

Checklist

• [x] My code adheres to the coding and style guidelines of the project.
• [x] I have performed a self-review of my own code.
• [x] My changes generate no errors/warnings/merge conflicts.