[ruby/reline] Emulate Unix like terminals that sends Alt+key as \e+key

https://github.com/ruby/reline/commit/dc2cf90fa6

lib/reline/windows.rb

@@ -226,6 +226,8 @@ class Reline::Windows
     # no char, only control keys
     return if key.char_code == 0 and key.control_keys.any?
 
+    @@output_buf.push("\e".ord) if key.control_keys.include?(:ALT)
+
     @@output_buf.concat(key.char.bytes)
   end