docs/debbugging.md: fix the format of an example launch.json

Change-Id: I235fb4960de994f84a70e6b1460ed52b5a8ca3b1
GitHub-Last-Rev: 2cde5de
GitHub-Pull-Request: golang#2774
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/495636
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Suzy Mueller <suzmue@golang.org>
Auto-Submit: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>

docs/debugging.md

@@ -492,19 +492,19 @@ your project lives in `/path/to/actual/helloWorld`, but the project is open in
 vscode under the linked folder `/link/to/helloWorld`, you can add the following
 to your config to set breakpoints in the files in `/link/to/helloWorld`:
 
-```
+```json
 {
     "name": "Launch with symlinks",
     "type": "go",
     "request": "launch",
     "mode": "debug",
     "program": "/path/to/actual/helloWorld",
     "substitutePath": [
-  {
-   "from": "/link/to/helloWorld",
-   "to": "/path/to/actual/helloWorld",
-  },
- ],
+        {
+            "from": "/link/to/helloWorld",
+            "to": "/path/to/actual/helloWorld"
+        }
+    ]
 }
 ```