docs: add news item and link release notes for mesa 10.6.3

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
diff --git a/docs/relnotes.html b/docs/relnotes.html
index 1acbce0..8355f11 100644
--- a/docs/relnotes.html
+++ b/docs/relnotes.html
@@ -21,6 +21,7 @@
 </p>
 
 <ul>
+<li><a href="relnotes/10.6.3.html">10.6.3 release notes</a>
 <li><a href="relnotes/10.6.2.html">10.6.2 release notes</a>
 <li><a href="relnotes/10.5.9.html">10.5.9 release notes</a>
 <li><a href="relnotes/10.6.1.html">10.6.1 release notes</a>