[css-text-3] Cross link terminology

Closes #4765

Author: frivoal

css-text-3/Overview.bs

@@ -2639,7 +2639,7 @@ Line Breaking Details</h3>
         <strong>기준을</strong> “글자” 또는 “어절” 단위로 한다.</pre>
 
       <p>Ethiopic similarly has two styles of line-breaking,
-        either only breaking at word separators (''word-break: normal''),
+        either only breaking at [=word separators=] (''word-break: normal''),
         or also allowing breaks between letters within a word (''word-break: break-all'').
       <pre>
         ተወልዱ፡ኵሉ፡ሰብእ፡ግዑዛን፡ወዕሩያን፡