[css-fonts-4] Add missing numeric range annotations

[cdoublev]

A numeric range is missing for the <integer> in <feature-tag-value>:

<feature-tag-value> = <string> [ <integer> | on | off ]?

If present, a value indicates an index used for glyph selection. An <integer> value must be 0 or greater.

A numeric range is missing for the <angle> in font-style in @font-face:

Value: auto | normal | italic | oblique [ <angle>{1,2} ]?

The meaning of the values for these descriptors are the same as those for the corresponding font properties [...]. If specified values are out of range of the accepted values of the property of the same name, the descriptor is treated as a parse error.

[w3cbot]

svgeesus marked as non substantive for IPR from ash-nazg.