Entity string might be mistakenly understood as a key:value object

[vnedelcu-ro]

Hey mate,

Thank you so much for your work. This card is really great. I've actually missed something like this for a while.
But I do have a small concern about the configuration.
Considering that hass works with YAML files and the config for this card contains lines like - moisture:sensor.plant_1_moisture, one (like me) might mistakenly believe that that's a key: value object, which is not. In the code that's actually treated as a whole string. Maybe, to clear up confusion, it can be either specified really visible in the readme file that those are array of strings or be treated as a key:value object in the code.
Just an idea, to prevent other people to loose a few hours trying to understand why the card is not working, lol.

Thanks