added project files and directory hierarchy
added Field to registrar
added abstract model class to models
added field_id to fields
added Alien model to models
added prompt method to console
added __all_models__ with available list of models
added get_models to registrar
added find_modules to registrar
added load_class to pyregistrar
trimmed _format from extension names
added plain extension
renamed test to match names
fixed plain extension
fixed import error and added pdf extension
added register to registrar
added main to console
added main to registrar
finalised script register
modified spacing in extension output