First release!

Added

• Supports all instructions with the exception of floating-point ones.
• Passes a large part of the official test suite (spectest 1.0):
  • 4482 of 4490 binary parser tests,
  • 301 of 942 validation tests (no full validation implemented yet),
  • 6381 skipped due to containing floating-point instructions or testing text format parser.
• Tools included:
  • fizzy-bench for benchmarking
  • fizzy-spectests for executing the official test suite
  • fizzy-unittests for running unit tests
• It is missing a public API (the embedder API) and thus not ready yet for integration.