updated the docs of the grid options and the stellar types

"""

Module that contains the default options for the population grid code, 

Module that contains the default options for the population grid code along with the description for these options, in the form of dictionaries: 

    - grid_options_defaults_dict: dictionary containing the default values for all the options

    - grid_options_descriptions: dictionary containing the description for these options.

along with a dictionary containing descriptions for each of the parameters, and some utility functions:

There are several other functions in this module, mostly to generate help texts or documents:

    - grid_options_help: interactive function for the user to get descriptions for options 

    - grid_options_description_checker: function that checks that checks which options have a description.

    - write_grid_options_to_rst_file: function to generate the .rst document for the docs

With this its also possible to automatically generate a pdf file containing all the setting names + descriptions. 

# Grid options functions

# Utility functions

def grid_options_help(option):

def grid_options_help(option: str) -> str:

    """

    Function that returns the description of a grid option

    Function that prints out the description of a grid option. Useful function for the user.

    Args:

        option: which option you want to have the description of

    """

    option_keys = grid_options_defaults_dict.keys()

        else:

            print(grid_options_descriptions[option])

def grid_options_description_checker(print_info=True):

def grid_options_description_checker(print_info: bool=True) -> int:

    """

    Function that checks which descriptions are missing 

    Args:

        print_info: whether to print out information about which options contain proper descriptions and which do not

    Returns:

        the amount of undescribed keys

    """

    # Get the keys

    option_keys = grid_options_defaults_dict.keys()

    description_keys = grid_options_descriptions.keys()

    # 

    undescribed_keys = list(set(option_keys)-set(description_keys))

    if undescribed_keys:

            print("Total description progress: {:.2f}%%".format(100 * len(description_keys)/len(option_keys)))

    return len(undescribed_keys)

def write_grid_options_to_rst_file(output_file):

def write_grid_options_to_rst_file(output_file: str) -> None:

    """

    Function that writes the descriptions of the grid options to a rst file

    Tasks:

        TODO: seperate things into private and public options

    Args:

        output_file: target file where the grid options descriptions are written to

    """

    # Get the options and the description

"""

Module containing stellar type dicts

Module containing two stellar type dicts:

    - STELLAR_TYPE_DICT: dictionary with long names

    - STELLAR_TYPE_DICT_SHORT: dictionary with short names/abbreviations

"""

STELLAR_TYPE_DICT = {