Update rpg_game.py + Add scenes.py

[yaong-27]

Rpg_game.py

• Added the str_c function, that has the task to facilitate the coloring operation applied to Strings or Integer values
• Transferred scenes_list into scenes.py for better code organization
• Added the get_scenes method that retrieves the scenes list from scenes.py
• Fixed a bug related to the generation of the index of scene_list, using len(scene_list) - 1
• Fixed some minor typos

Scenes.py

It's a module file that has the task to store and transfer the scenes list to the main program.
However, it would be preferable to use a text file or a JSON one in case of a bigger list of scenes.