Add Rust highlighting (#7125)

rfwatson · techknowlogick · commit 8bf405986e99 · 2019-06-04T17:01:47.000-04:00
diff --git a/modules/highlight/highlight.go b/modules/highlight/highlight.go
@@ -51,6 +51,7 @@ var (
 		".php":   {},
 		".py":    {},
 		".rb":    {},
+		".rs":    {},
 		".scss":  {},
 		".sql":   {},
 		".scala": {},
