added define CUSTOM_MODEL_NAME

updated description of difference between PureSpa models

updated dependencies (Arduino Core for ESP8266 3.1.2, ArduinoJson 6.2…

…1.3)

moved config data into src folder (required by Arduino ESP8266 Little…

…FS Filesystem Uploader)

added support for PlatformIO

Co-Authored-By: Cristian Alonso <fizcris@gmail.com>

allow MQTT port config entry to be optional (backward compatiblity)

updated firmware and MQTT paragraphs

improve reliablity of setting desired water temperatur

- introduce constant PureSpaIO::BUTTON_FRAMES to make PureSpaIO::TOTAL_FRAMES depended on pool model
- introduce constant PureSpaIO::BUTTON::PRESS_SHORT_COUNT for changing the desired water temperature
- method PureSpaIO::updateButtonState() extracted from PureSpaIO::decodeButton()
- PureSpaIO::setDesiredWaterTempCelsius: calculate changeTries depeding on inital temperature delta
- PureSpaIO::changeWaterTemp: set tries and toggleTempUp/Down based on PRESS_SHORT_COUNT
- PureSpaIO::changeWaterTemp: clear toggleTempUp/Down when PRESS_SHORT_COUNT is reached
- PureSpaIO::changeWaterTemp: wait for buzzer until delta to BUTTON::PRESS_COUNT has expired

set desired water temperature without interrupting MQTT connection

- PureSpaIO::setDesiredWaterTempCelsius: read back actual setpoint
- PureSpaIO::decodeButton: cancel temp up/down if buzzer is on
- PureSpaIO::decodeButton: reduced reply pulse length from 3 to 2 µs
- PureSpaIO::PRESS_COUNT: reduced from 21 to 19 button frames

use matrix strategy for GitHub Action to test build for all supported…

… models