Plants waterer (dual flusher) elements

Parts for the DIY Arduino-based device described in [this blog post](https://aleksandr.ru/blog/domashnyaya_polivalka_rasteniy).

Playable [demo with emulator](https://wokwi.com/projects/389538444219182081) and [source code at github](https://github.com/Aleksandr-ru/dual-flusher).

Hardware:

* LGT8F328P or Arduino Nano
* Optional [heatsink](https://aliexpress.ru/item/1005005979193670.html?sku_id=12000035148789851)
* [Relay module](https://aliexpress.ru/item/32890655145.html?sku_id=10000007058962150)
* [0.91" OLED](https://aliexpress.ru/item/1005003650234451.html)
* [Encoder](https://aliexpress.ru/item/32915420023.html?sku_id=12000027702263272)
* 2x [water pump](https://aliexpress.ru/item/1005005106478272.html?sku_id=12000031682224885) + 1N4001 diode + 0.1uF ceramic capacitor
* [Pipes](https://aliexpress.ru/item/1005004782664605.html?sku_id=12000030467911145) and [filter](https://aliexpress.ru/item/1005004204752357.html?sku_id=12000028370914152)
* 2x [soil moisture sensor](