Add the byebug line # to make the output clickable

Adding the exact line number of the byebug statement to the end of the filename on the output makes the statement clickable in IDE's and editors supporting this functionality. Currently clicking the path goes to the top of the file. With the modification, clicking takes the user to the exact byebug line in the file.

lib/byebug/commands/list.rb

@@ -113,7 +113,7 @@ def move(line, size, direction = "+")
     # @param max [Integer] Upper bound
     #
     def display_lines(min, max)
-      puts "\n[#{min}, #{max}] in #{frame.file}"
+      puts "\n[#{min}, #{max}] in #{frame.file}:#{(max+min)/2}"
 
       puts source_file_formatter.lines(min, max).join
     end