Changelog

rename various things to get a more coherent and intuitive workflow: bf_test() -> bf_map(), operator -> protocol, bf_internal -> bf_pcl
new function bf_standards() to interact with github to pull, push or list community standards base on the github personal access token.
formalise the bitfield operators into a protocol, i.e., a standardised list with a dedicated .validateProtocol() function.

merge all functions into bf_test().
remove bf_standards() and bf_stds.
merge the previous test-functions into a structure that is similar to bd_stds, i.e., a list with instructions and documentation for that operation/test (bf_internal), which will be called in bf_test().
revise determination of encoding with more user-friendly interface. Now, everything is specified in bf_test() with the ... argument; documentation explains everything in much more detail.

include the .rast() function for simple handling of gridded objects.
unit tests for all functions.
introduction of a small set of standard encodings in bf_stds and the function bf_standard() to create flags from those.

major revision of the template function body for the bitfield operators
more options for bitfield operators, such as the possibility to specify an NA-value and the position in the bitfield, and a custom description
more stringent provenance handling, now provenance is reported as a combination of the Action name and the parameters that are used (following PROV terminology and logic)
revision of the bf_decode() output reporting, now with a more user-friendly return value
full documentation and functionality of all functions (except auto determination of floating-point encoding for numeric values)
document also MD5 checksum for registries

revise various functions
improve text (readme/vignette)
change naming of the functions
correct terminology, the class is not the bitfield but instead an array or registry that contains information about the bitfield. Hence, I renamed it to registry
use attributes to capture a bitflag description and name

bitfield 0.6.0