[css-ui-4] Fix cross spec link

Author: frivoal

css-ui-4/Overview.bs

@@ -263,7 +263,7 @@ Applies to: all elements
 Inherited: no
 Percentages: N/A
 Computed value: The computed value for ''outline-color/invert'' is ''outline-color/invert''.
- For <<color>> values, see <a>resolving color values</a> in [[!CSS-COLOR-4]].
+ For <<color>> values, see [[!CSS-COLOR-4#resolving-color-values]] in [[!CSS-COLOR-4]].
 Animation type: by computed value
 </pre>
 
@@ -932,7 +932,7 @@ Applies to: all elements
 Inherited: yes
 Percentages: N/A
 Computed value: The computed value for ''caret-color/auto'' is ''caret-color/auto''.
- For <<color>> values, see <a>resolving color values</a> in [[!CSS-COLOR-4]].
+ For <<color>> values, see [[!CSS-COLOR-4#resolving-color-values]] in [[!CSS-COLOR-4]].
 Animation Type: by computed value
 </pre>