Removed optional

Updated include guards

Added optional support for the read method

Updated CMake minimum version to 3.14 to support FetchContent_MakeAva…

…ilable

Fixed constness of Write method

Updated class name to CircleBuf. Updated includes to more accurately …

…capture those used.

Updated preprocessor directives to more easily define when Arduino ID…

…E is used. Updated README to better detail the Arduino support.

Tweaking preprocessor directives to better catch when Arduino IDE is …

…used

Updated directory structure and README to support Arduino library bui…

…lds, in addition to CMake

Updated to namespace bfs