[ENHANCEMENT] Update and improve the setting labels.

[ChiCheng45]

In PR #280 the script generation adds the setting label description as comments. I think we need to go through them and change/update them. In many cases the labels defaults to the parameter keyword name.

parameters = {
    'atom_charges': {0: 0.5, 1: 1.2, 2: -0.2},          # atom charges
    'atom_selection': 'atom_index 0,1,2',               # atom selection
    'frames': (0, 10, 1),                               # Subset of frames to be selected (first, last, step size)
    'output_files': ('OUTPUT_FILENAME', ['MDAFormat', 'ASCIIFormat']),  # Output filename and formats (filename, [format, ...])
    'running_mode': ('monoprocessor', 1),               # running mode
    'trajectory': 'INPUT_FILENAME.mdt',                 # MDANSE trajectory file
}

In the above example some more helpful text for the atom charges parameter would be useful.

[ChiCheng45]

Closing as this is perhaps too general of an issue and should be done continuously.