feat: linux SDL2 support

[theiereman]

Hey, I saw #3 and I thought I could help for the Linux SDL2 part.

I also noticed that the animation wasn't finishing properly on my 144hz screen so I fixed it.

I can't test Windows SDL2 integration so I didn't add the code to manage it, sorry! Also, please test if the darwin call is ok to manage macOS detection.

NB : the fiddle gem dependency was added because I got that warning /home/david/.rbenv/versions/3.3.5/lib/ruby/3.3.0/reline.rb:9: warning: fiddle was loaded from the standard library, but will no longer be part of the default gems starting from Ruby 3.5.0.