Empty HTML template from tutorial otuput

Un-named template being emitted from the CNB tutorial https://github.com/heroku/buildpacks/blob/8c6a4a86aa6ccaff6926add4761e79601dfa4851/docs/go/README.md:

```
$ docker run -it --rm --env PORT=5006 -p 5006:5006 my-image-name
[GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production.
- using env: export GIN_MODE=release
- using code: gin.SetMode(gin.ReleaseMode)

[GIN-debug] Loaded HTML Templates (4):
- index.tmpl.html
- nav.tmpl.html
-
- header.tmpl.html

[GIN-debug] GET /static/*filepath --> github.com/gin-gonic/gin.(*RouterGroup).createStaticHandler.func1 (2 handlers)
[GIN-debug] HEAD /static/*filepath --> github.com/gin-gonic/gin.(*RouterGroup).createStaticHandler.func1 (2 handlers)
[GIN-debug] GET / --> main.main.func1 (2 handlers)
[GIN-debug] [WARNING] You trusted all proxies, this is NOT safe. We recommend you to set a value.
Please check https://pkg.go.dev/github.com/gin-gonic/gin#readme-don-t-trust-all-proxies for details.
[GIN-debug] Listening and serving HTTP on :5006
```

Specifically this:

```
- index.tmpl.html
- nav.tmpl.html
-
- header.tmpl.html
```

This output is unexpected to me and might be to other users. Do we know where that's coming from? Can we suppress it or otherwise provide a name for it?