[css-fonts-5][editorial] dedup ids

Author: svgeesus

css-fonts-5/Overview.bs

@@ -712,7 +712,7 @@ Acknowledgments</h2>
 Changes
 </h2>
 
-<h3 id="changes">Changes since the <a href="https://www.w3.org/TR/2021/WD-css-fonts-5-20211221/">WD of 21 December 2021</a> </h3>
+<h3 id="changes-20211221">Changes since the <a href="https://www.w3.org/TR/2021/WD-css-fonts-5-20211221/">WD of 21 December 2021</a> </h3>
 
 <ul>
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