docs: prefer lowercase html tags

Signed-off-by: Brian Paul <brianp@vmware.com>
diff --git a/docs/lists.html b/docs/lists.html
index d288cc8..d89bcff 100644
--- a/docs/lists.html
+++ b/docs/lists.html
@@ -63,7 +63,7 @@
 
 <br>
 
-<H1>OpenGL Forums</H1>
+<h1>OpenGL Forums</h1>
 
 <p>
 Here are some other OpenGL-related forums you might find useful: