Fix included files on bundled gem

Signed-off-by: stephann <3025661+stephannv@users.noreply.github.com>

Author: stephannv

ruby_ui.gemspec

@@ -7,7 +7,11 @@ Gem::Specification.new do |s|
   s.description = "Ruby UI is a UI Component Library for Ruby developers. Built on top of the Phlex Framework."
   s.authors = ["George Kettle"]
   s.email = "george.kettle@icloud.com"
-  s.files = Dir["lib/**/*.{rb,yml,erb}", "tasks/**/*.rake"]
+  s.files = Dir[
+		"README.md",
+		"LICENSE.txt",
+		"lib/**/*"
+	]
   s.require_path = "lib"
   s.homepage =
     "https://rubygems.org/gems/ruby_ui"