[csswg-drafts] [filter-effects] Fix the 'tableValues' description of transfer functions (#4186)

RazrFalcon has just created a new issue for https://github.com/w3c/csswg-drafts:

== [filter-effects] Fix the 'tableValues' description of transfer functions ==
- https://www.w3.org/TR/filter-effects-1/#element-attrdef-fecomponenttransfer-tablevalues

For `tableValues`, the doc states that:

>When type="table", the list of <number> s v0,v1,...vn

But `tableValues` are used by the [discrete](https://www.w3.org/TR/filter-effects-1/#attr-valuedef-type-discrete) type too.

>For discrete, the function is defined by the step function given in the attribute tableValues

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/4186 using your GitHub account