SHTC3 Sensor Placement

[urish]

I've been running the awesome Rust Board for several hours, and as expected, the ESP32-C3 module gets a bit warm. Unfortunately, this affects the SHTC3 sensor readings in a significant way (I measured more than 5 °C error, which also greatly affects the relative-humidity reading, as it's temperature-compensated).

I suggest moving the SHTC3 as far as possible from the ESP32-C3 module, to mitigate this issue. I don't have any thermal imaging hardware here, but it seems like the bottom of the board, next to the USB-C connector, is more or less at the ambient temperature, so it might be a better place for the SHTC3 in future revisions of the board.