Restructured the folders and files to use a common project structure, updated readme.

README.md

parser/parser-big-dft/bigdftparser/parser.py

parser/parser-big-dft/bigdftparser/scalainterface.py

...rser-big-dft/bigdftparser/versions/bigdft18/mainparser.py

regtests/bigdft_1.8/periodicity/free/forces_posinp.xyz

regtests/bigdft_1.8/periodicity/free/input_minimal.yaml

regtests/bigdft_1.8/periodicity/free/output.out

regtests/bigdft_1.8/periodicity/free/posinp.xyz

regtests/bigdft_1.8/periodicity/free/time.yaml

regtests/bigdft_1.8/periodicity/periodic/forces_posinp.xyz

regtests/bigdft_1.8/periodicity/periodic/input_minimal.yaml

regtests/bigdft_1.8/periodicity/periodic/output.out

regtests/bigdft_1.8/periodicity/periodic/posinp.xyz

regtests/bigdft_1.8/periodicity/periodic/time.yaml

regtests/bigdft_1.8/periodicity/surface/forces_posinp.xyz

regtests/bigdft_1.8/periodicity/surface/input_minimal.yaml

regtests/bigdft_1.8/periodicity/surface/output.out

regtests/bigdft_1.8/periodicity/surface/posinp.xyz

regtests/bigdft_1.8/periodicity/surface/time.yaml

regtests/bigdft_1.8/single_point/forces_posinp.xyz