feat: add dependency

Author: Mark24Code

convert2ascii.gemspec

@@ -34,7 +34,9 @@ Gem::Specification.new do |spec|
 
   # Uncomment to register a new dependency of your gem
   # spec.add_dependency "example-gem", "~> 1.0"
-
+  spec.add_dependency "rmagick", "~> 6.0.1"
+  spec.add_dependency "rainbow", "~> 3.1.1"
+  spec.add_dependency "async", "~> 2.21"
   # For more information and examples about making a new gem, check out our
   # guide at: https://bundler.io/guides/creating_gem.html
 end