docs: convert last traces of progs to mesa/demos repository

v2: fix typo

Reviewed-by: Brian Paul <brianp@vmware.com>
diff --git a/docs/osmesa.html b/docs/osmesa.html
index 0ec67c4..b0609cf 100644
--- a/docs/osmesa.html
+++ b/docs/osmesa.html
@@ -34,8 +34,7 @@
 </p>
 
 <p>
-There are several examples of OSMesa in the <code>progs/osdemos/</code>
-directory.
+There are several examples of OSMesa in the mesa/demos repository.
 </p>