This pull request adds support for several new M5Stack boards and improves hardware abstraction, especially for audio and IO expander handling. It also updates dependencies and refactors the code to use the new M5IOE1_Class for IO expander operations, providing more robust and maintainable hardware control.

New Board Support:

• Added support for the following boards: M5STAMPS3S3Bat, M5STAMPS3Mini, M5STAMPPLC, M5PaperDIY, M5AirQ, M5StackChan, M5ChainCaptain, M5DualKey, M5STAMPC5, M5ToughC5, M5STAMPC6, M5STAMPP4, M5UnitPoEP4 in both documentation and code, including board detection and initialization logic. [1] [2] [3] [4] [5]

Audio and Microphone Handling Improvements:

• Added new callback implementations for enabling/disabling speakers and microphones on M5ChainCaptain and M5PaperMono, with correct power sequencing and IO expander usage. [1] [2] [3] [4] [5]

IO Expander Refactor:

• Refactored code to use the new M5IOE1_Class for all IO expander operations instead of direct I2C register manipulation, improving maintainability and abstraction. [1] [2] [3] [4]

Dependency Updates:

• Updated M5GFX dependency to version >=0.2.26 and bumped the library version to 0.2.19 in all relevant files. [1] [2] [3]

Documentation:

• Updated README.md to reflect all newly supported boards and features.

These changes expand board compatibility, improve hardware abstraction, and ensure the library is up to date with its dependencies.