Added description of CLI-option --chaing-groups to documentation.
Added description of CLI-option --chaing-groups to documentation.

mittinatten/freesasa,mittinatten/freesasa,JoaoRodrigues/freesasa,JoaoRodrigues/freesasa,JoaoRodrigues/freesasa,mittinatten/freesasa,mittinatten/freesasa,JoaoRodrigues/freesasa