docs/debugging.md: fix missing "" in example

missing "" in the substitutePath example

Change-Id: I0ef388dcb78e3843541803dc301c0e8b24051045
GitHub-Last-Rev: 9bbfd29
GitHub-Pull-Request: #2336
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/417315
Reviewed-by: Hyang-Ah Hana Kim <[email protected]>
Reviewed-by: Jamal Carvalho <[email protected]>

Author: hellodudu

docs/debugging.md

@@ -581,7 +581,7 @@ Use the following `launch` configuration to tell `dlv` to execute a binary preco
   "mode": "exec",
   "program": "/absolute/path/to/remote/workspace/program/executable",
   "substitutePath": [
-      { "from": ${workspaceFolder}, "to": "/path/to/remote/workspace" },
+      { "from": "${workspaceFolder}", "to": "/path/to/remote/workspace" },
       ...
   ]
 }