Merge branch 'feature/#615-addition-of-etl--expected' of https://github.com/ETLCPP/etl into feature/#615-addition-of-etl--expected
# Conflicts:
# arduino/library-arduino.json
# arduino/library-arduino.properties
# include/etl/expected.h
# include/etl/private/variant_variadic.h
# include/etl/result.h
# include/etl/version.h
# library.json
# library.properties
# support/Release notes.txt
# version.txt
