Update

Signed-off-by: Peter Atashian <retep998@gmail.com>
crates.io

Signed-off-by: Peter Atashian <retep998@gmail.com>
Refactor Node into separate module.

Signed-off-by: Peter Atashian <retep998@gmail.com>
Docs

Signed-off-by: Peter Atashian <retep998@gmail.com>
Version bump 0.2.1

Signed-off-by: Peter Atashian <retep998@gmail.com>
Renamed LICENSE.txt to LICENSE.md for consistency.
Implemented std::error::Error for Error.
Added documentation.
Finished basic documentation.