[css-text] User better image for uyghur example

As suggested in #5973

Author: frivoal

css-text-3/Overview.bs

@@ -4708,12 +4708,16 @@ Hyphenation: the 'hyphens' property</h3>
 	<div class="example">
 		For example, if the Uyghur word &ldquo;داميدى&rdquo;
 		were hyphenated, it would appear as
-		<img src="images/uyghur-hyphenate-joined.png"
+		<img src="images/uyghur-hyphenate-joined.svg"
+		     height=608
+		     style="height: 3.5em; background: white;"
 		     alt="[isolated DAL + isolated ALEF + initial MEEM +
 		          medial YEH + hyphen + line-break + final DAL +
 		          isolated ALEF MAKSURA]">
 		not as
-		<img src="images/uyghur-hyphenate-unjoined.png"
+		<img src="images/uyghur-hyphenate-unjoined.svg"
+		     height=608
+		     style="height: 3.5em; background: white;"
 		     alt="[isolated DAL + isolated ALEF + initial MEEM +
 		          final YEH + hyphen + line-break + isolated DAL +
 		          isolated ALEF MAKSURA]">