patch 9.0.0922: Mermaid files are not recognized

Problem:    Mermaid files are not recognized.
Solution:   Add patterns for Mermaid. (Crag MacEachern)
diff --git a/src/version.c b/src/version.c
index cde6e1d..c73f1c4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    922,
+/**/
     921,
 /**/
     920,