Created topic-based documentation:
- basics.rst: core concepts and fundamental usage
- cyclic_programming.rst: PLC-style programming with Cycletools
- event_programming.rst: event-driven patterns and callbacks
- advanced.rst: gateway IOs, replace_io_file, watchdog management
- installation.rst and quickstart.rst: getting started guides
Added complete API reference in docs/api/:
- All device classes including ModularBaseConnect_4_5 and GatewayMixin
- I/O, helper, and main class documentation
Enhanced Sphinx configuration with RTD theme and improved autodoc settings.
Removed auto-generated modules.rst and revpimodio2.rst.
