mizu-core 1.0.0

The core library implementation of all Gameboy emulation for Mizu
Documentation
# Changelog
All changed that occur when changing the variable `SAVE_STATE_VERSION`.
Which are changes that occur to the structure of the save state file format.

## [2] - 2021-05-02
- Added compression for the save content, using `zstd`.
- This version can handle loading from version `1`.

## [1] - 2021-04-25
- The start implementation of save state.