v0.0.5 impl arrays, maps, and shift-decoding refactor!

• implemented arrays and maps
• introduced function core:shift(byte[] data) returns [byte first, byte[] rest];
• refactored decoding to utilize core:shift, and pop bytes off data as they're consumed and decoded

What's Changed

• impl arrays and maps by @DrewMcArthur in #1

Full Changelog: v0.0.4...v0.0.5