docs: update dlv-dap.md

dlv-dap --log-output options requires the --log parameter, updated doc to reflect this

Change-Id: I47cf5b3d0da28ae4cdfc80c02c9d56e7b427779b
GitHub-Last-Rev: 27235c98bb891306fa031af7fad91b0e70a6c23c
GitHub-Pull-Request: golang/vscode-go#1488
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/318030
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/dlv-dap.md b/docs/dlv-dap.md
index c4168ad..f57d475 100644
--- a/docs/dlv-dap.md
+++ b/docs/dlv-dap.md
@@ -135,7 +135,7 @@
 If you are having issues with seeing logs and or suspect problems in extension's integration, you can start Delve DAP server from a separate terminal and configure the extension to directly connect to it.
 
 ```
-$ dlv-dap dap --listen=:12345 --log-output=dap
+$ dlv-dap dap --listen=:12345 --log --log-output=dap
 ```
 
 ```json5