x/website: typo in workspaces tutorial

[algonzalez]

What version of Go are you using (go version)?

$ go version
go version go1.18 windows/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
set GOARCH=amd64
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOAMD64=v1

What did you do?

Reading tutorial on workspaces; line https://github.com/golang/website/blob/76352824d2e26b9d9407709835151c27642d45b3/_content/doc/tutorial/workspaces.md?plain=1#L193 does not appear to be accurate.

What did you expect to see?

Text for creating a file such as:

Create a `toupper.go` file in the `workspace/example/stringutil` directory with the following contents:

What did you see instead?

Text for adding a folder:

 Add a new folder to the `workspace/example/stringutil` directory containing the following contents:

[seankhliao]

This was fixed in CL 393360