[feature] improve documentation

[ezpzbz]

I will add few more sections to the documentation:

• Full example of running calculation using SinglefileData
• Full example of running calculation using StructureData and proving charges as input parameter
• A complete script and example on how to use resulting structures for further calculations with other plugins
• Full example of a case with magnetic enumeration

[ezpzbz]

Sample output dict for documentation:

Groups

"Chemical_formula": {
        "Initial": "Al4Ca4O14Si2",
        "Supercell": "Al8Ca8O28Si4"
    },
    "Crystallographic_groups": {
        "Group1": {
            "Site1": {
                "Actual_occupancy": 0.5,
                "Initial_occupancy": 0.5,
                "Symbol": "Al10",
                "Type": {
                    "distributed": {
                        "considered_sites": "1",
                        "total_sites": "2"
                    }
                }
            },
            "Site2": {
                "Actual_occupancy": 0.5,
                "Initial_occupancy": 0.5,
                "Symbol": "Si11",
                "Type": {
                    "distributed": {
                        "considered_sites": "1",
                        "total_sites": "2"
                    }
                }
            }
        },
        "Group10": {
            "Site1": {
                "Actual_occupancy": 1.0,
                "Initial_occupancy": 1.0,
                "Symbol": "Ca3",
                "Type": "FIXED"
            }
        },

Symmetry and structures

"Number_of_structures": {
        "symmetrically_distinct": 8,
        "total_combinations": 16
    },
    "Number_of_symmetry_operations": 2,
    "Random_seed": 2225839783,
    "Structures_info": {
        "ia07": {
            "coulombic_energy": -1693.13,
            "crystal_system": "monoclinic",
            "degeneracy": 2,
            "lattice_type": "monoclinic",
            "space_group_symbol": "Cm"
        },
        "if00": {
            "coulombic_energy": -1694.042,
            "crystal_system": "tetragonal",
            "degeneracy": 2,
            "lattice_type": "tetragonal",
            "space_group_symbol": "P-42_1m"
        },
"Supecell_total_charge": 0,
    "coulombic_energy_unit": "eV"