Fix Typo in rust language guide (#18383)

Release Notes:

- N/A

docs/src/languages/rust.md

@@ -23,8 +23,8 @@ The following configuration can be used to change the inlay hint settings for `r
         "inlayHints": {
           "maxLength": null,
           "lifetimeElisionHints": {
-            "enable": "skip_trivial"
-            "useParameterNames": true,
+            "enable": "skip_trivial",
+            "useParameterNames": true
           },
           "closureReturnTypeHints": {
             "enable": "always"