[css-transforms] Minor syntax rewrite

[cdoublev]

• add missing group around function arguments
• use multipliers instead of repeating symbols

[tabatkins]

You don't need a group around a function's arguments. In this particular case it's becuase there's nothing to group in the first place, but more generally function syntax implicitly groups its arguments. (This is a relatively recent addition to the grammar, reflecting what a lot of people were accidentally doing anyway.)

I also think it's fine to repeat arguments a little, so long as it's not a clarity issue. It's easier to read <length> , <length> than <length>{1,2}, in my opinion. So either way is correct, but none of the examples here look like they'd particularly benefit from changing.

[cdoublev]

I missed this change, sorry. Actually it is <length>#{1,2}, which requires to know the meaning of #, instead of <length> , <length>?, which requires to know about the comma-elision rule, but I admit the latter is still easier to read. Thanks for the feedback.