.vscode/launch.json: Launch tools/generate

We use our debugger to debug go program!

Change-Id: I731dde2c5f915c8017c4b95470288bdfa2e3b19f
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/328489
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Suzy Mueller <suzmue@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>

Author: hyangah

.vscode/launch.json

@@ -1,6 +1,14 @@
 {
 	"version": "0.2.0",
 	"configurations": [
+		{
+			"name": "Launch tools/generate",
+			"type": "go",
+			"request": "launch",
+			"mode": "debug",
+			"program": "${workspaceFolder}/tools/generate.go",
+			"cwd": "${workspaceFolder}"
+		},
 		{
 			"name": "Launch Extension",
 			"type": "extensionHost",