Interphon

Update documentation and tutorials

Fix minor errors and refine docstring

1. Fix minor errors
2. Add 'write_mode_displace' function in mode analysis
3. Refine thermal_properties analysis
4. Add comments and docstring in all program files

1. Fix error in searching the plane group operations
2. Add example data using symmetry functionality

1. Refine exception handling related to symmetry functionality
2. Add unittest

1. Refine the symmetry functionality
2. Add full examples