Fix doc, Tutorials / Create a Rust worker

[taisukef]

Thank you for the exciting project!

[vmwclabot]

@taisukef, you must sign our contributor license agreement before your changes are merged. Click here to sign the agreement. If you are a VMware employee, read this for further instruction.

[vmwclabot]

@taisukef, we have received your signed contributor license agreement. It will be reviewed by VMware shortly. Another comment will be added to the pull request to notify you when the merge can proceed.

[vmwclabot]

@taisukef, VMware has approved your signed contributor license agreement.

[gzurl]

Thanks @taisukef for your patch! LGTM!