firmware-base/scripts/modbus.md

Context

• ESP-32, Platform.io, C17

• Create a comprehensive documentation for all Modbus related classes, with diagrams (mermaid, no braces in node names), in ./docs/modbus/readme.md

• Create a performance analysis, in ./docs/modbus/performance.md

• Find bottlenecks and improvements, ./docs/modbus/todos.md