Can't use with create react app etc

[rykener]

currently Django Manifest Loader can only consume the default manifest file as generated by WebpackManifestPlugin. Instead, it should have a series of different loaders it can use, so that a) loaders can be developed for other default types of manifest files, like create react apps manifest and b) so that users can write their own manifest loaders if the provided loaders don't work for them.

# settings.py

from manifest_loader.loaders import CREATE_REACT_APP

MANIFEST_LOADER = { 
    'loader': CREATE_REACT_APP,
}