Output format: Are width/height always integers, or can they be floats?

In the output format, are `width` and `height` guaranteed to always be integers, or can they be floating point numbers?

Context: I'm a back-end .NET developer needing to parse Editor.js documents. Back-end deserialization/parsing in strongly typed languages requires me to choose to deserialize to either `int` (the simplest and most constrained) or `float` (the most general, but unnecessary if it's guaranteed to always be an integer). If these properties are guaranteed to always be `int`, then that guarantee should ideally be added to the readme to ensure it is formalized and kept in the future.