[css-fonts-4][editorial] Use correct syntax <<system-family-name>> w3c#9292

Author: svgeesus

css-color-4/Overview.bs

@@ -719,6 +719,9 @@ Transparency: the 'opacity' property</h3>
 to explicitly tag an image as being in the sRGB color space,
 without including the sRGB ICC profile.
 
+Similarly, PNG specifies a compact means
+(the <a href=""></a> )
+
 Tagged RGB images,
 and tagged images using a transformation of RGB such as YCbCr,
 if the color profile or other identifying information is valid,

css-fonts-4/Overview.bs

@@ -1585,7 +1585,7 @@ Shorthand font property: the 'font' property</h3>
 <<'font-weight'>> ||
 <<font-stretch-css3>> ]? <<'font-size'>> [ / <<'line-height'>> ]? 
 <<'font-family'>> ] | 
-<<'system-family-name'>>
+<<system-family-name>>
 Initial: see individual properties
 Applies to: all elements and text
 Inherited: yes