I like it! Nice custom theme

[PySimpleGUI]

There's a new call that's been added (being added) that makes adding a theme entry easier.

def theme_add_new(new_theme_name, new_theme_dict):
    """
    Add a new theme to the dictionary of themes

    :param new_theme_name: text to display in element
    :type new_theme_name: (str)
    :param new_theme_dict: text to display in element
    :type new_theme_dict: (dict)
    """

I love that you added screenshots in your readme! 👍