Rewrite library with compatibility for all board

[awhitchurch]

This pull request modernizes the Arduino example code, updates configuration and documentation, and improves code consistency and maintainability for the ADS1293 ECG library. The changes include replacing legacy examples with updated versions, introducing editor and VSCode settings for consistent formatting, and updating keywords for better code completion and documentation.

Example and Documentation Updates:

• Replaced legacy demo examples (Example1-3leadECGstream-arduino-plotter.ino, Example2-5leadECGstream-arduino-plotter.ino, Example3-5leadECGstream-openview.ino) with new, clearer and more maintainable examples (Example-1-3leadECGstream-arduino-plotter.ino, Example-2-5leadECGstream-arduino-plotter.ino, Example-3-5leadECGstream-openview.ino) that use updated APIs, improved documentation, and support for both Arduino UNO and ESP32 platforms. [1] [2] [3] [4] [5] [6]

Keyword and API Consistency:

• Updated keywords.txt to reflect new and renamed API functions (e.g., getECGData, readDeviceID, disableChannel), improving code completion and documentation accuracy.

ECG Data Streaming Enhancements:

• Improved packet formatting and data streaming logic for both Arduino Plotter and OpenView examples, including proper little-endian packing and sign extension for 24-bit raw ECG data.

Platform Support Improvements:

• All new examples now include conditional logic for SPI pin configuration, supporting both Arduino UNO and ESP32 VSPI defaults for easier portability. [1] [2] [3]

Let me know if you have questions about any specific change or want to understand how the new examples work!