Add icons for each device

Perhaps icons (or emojis, although I don't think any is suitable) could be added to categorize those entries which support either the ESP32 or the ESP8266, as well as the upcoming model, the ESP32-S2. I'm thinking of something like: - [ESP-Dash](https://github.com/ayushsharma82/ESP-DASH) - Beautiful framework for creating remote dashboards. ICON HERE Instead of: - [ESP-Dash](https://github.com/ayushsharma82/ESP-DASH) - Beautiful framework for creating remote dashboards in the 8266.