docs: Import 10.2.4 release notes

And add a news item.
diff --git a/docs/relnotes.html b/docs/relnotes.html
index ba88d1a..ca00883 100644
--- a/docs/relnotes.html
+++ b/docs/relnotes.html
@@ -21,6 +21,7 @@
 </p>
 
 <ul>
+<li><a href="relnotes/10.2.4.html">10.2.4 release notes</a>
 <li><a href="relnotes/10.2.3.html">10.2.3 release notes</a>
 <li><a href="relnotes/10.2.2.html">10.2.2 release notes</a>
 <li><a href="relnotes/10.2.1.html">10.2.1 release notes</a>