[css-syntax-3][css-values-4] Add informative note about tokenization of negative 0

I cannot tell which behavior is "right", if there is one, and I cannot think of an example for which it could matter, but I feel like an informative note (something like the note removed in this commit) about removing the sign of 0⁻ in convert a string to a number is required, especially in regards to calculations because a consequence is that calc(1 / -0) is calc(infinity) instead of calc(-infinity), which matches the output in JS, which performs division according to the rules of IEEE 754-2019, whereas in Type Checking (CSS Values):

Math functions follow IEEE-754 semantics for these operations

• Dividing a positive value by zero produces +∞.
• Dividing a negative value by zero produces −∞.

[...]

In other words, multiplying or dividing with 0⁻ follows standard sign rules

Can you also please tell me if there is any other difference between convert a string to a number and JS Number(), please?

Read the CSS Syntax 3 “convert a string to a number” section alongside CSS Values 4 “Type Checking (CSS Values)” and the referenced commit. Determine whether the negative-zero behavior and its relationship to JavaScript Number() need an informative note. Done means the Working Group has resolved the wording and the relevant specification text is updated.