vs-code tasks: missed comma in the snippet

Just missed a comma in code snippet

Change-Id: I408c4aaa798ba19c3c73c19ac4d13bad396dabbc
GitHub-Last-Rev: 07d160c8b5e479f64374800fd9962ca53237e780
GitHub-Pull-Request: golang/vscode-go#699
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/259077
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Suzy Mueller <suzmue@golang.org>
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
Trust: Suzy Mueller <suzmue@golang.org>
diff --git a/docs/tasks.md b/docs/tasks.md
index 90fc8e8..79a6888 100644
--- a/docs/tasks.md
+++ b/docs/tasks.md
@@ -65,7 +65,7 @@
             "label": "run",
             "command": "go",
             "args": ["run", "${file}"],
-            "group": "build"
+            "group": "build",
             "type": "shell",
         },
         {