[css-break] Minimum values for `widows` & `orphans` properties should be 1, not 0

[cdumez]

Minimum values for widows & orphans properties should be 1, not 0:

• https://w3c.github.io/csswg-drafts/css-break/#widows-orphans

The value range says: <integer [0,∞]>, but I think it should be <integer [1,∞]>, given that the prose right under the table says:

Negative values and zero are invalid and must cause the declaration to be ignored.

[fantasai]

Thanks for the report! Fixed.

[Loirooriol]

This seems superfluous now:

Only positive integers are allowed as values of orphans and widows. Negative values and zero are invalid and must cause the declaration to be ignored.

[astearns]

It’s OK to say the same thing in grammar and prose (if they actually do match)