Add slimzsh

[elharion]

Many people use it on daily basis :) It's really good if someone is looking for something small and simple.

[k4m4]

Could you please:

• [x] Resolve conflicts.
• [x] Drop the A in the description.

Thanks! @elharion

[elharion]

Hey @k4m4. Done :) If there's anything more i could do please let me know. Cheers!