YAML values like `.inf` and `.nan` should be highlighted as number

[silverwind]

Describe the bug

YAML's infinity .inf is currently highlighted like a string, while it is technically a number so should be highlighted as such. See this and this for all possible "float" types of YAML, which could all be highlighted as number. The second page also lists this regexp:

 [-+]?([0-9][0-9_]*)?\.[0-9.]*([eE][-+][0-9]+)? (base 10)
|[-+]?[0-9][0-9_]*(:[0-5]?[0-9])+\.[0-9_]* (base 60)
|[-+]?\.(inf|Inf|INF) # (infinity)
|\.(nan|NaN|NAN) # (not a number)

To Reproduce

https://swapoff.org/chroma/playground/#eyJsYW5ndWFnZSI6IllBTUwiLCJzdHlsZSI6ImRyYWN1bGEiLCJ0ZXh0IjoiYTogc3RyaW5nXG5iOiAxXG5jOiAtMVxuZDogLmluZlxuZTogLS5pbmZcblxuIiwiY2xhc3NlcyI6ZmFsc2V9