Add note on Gateway API Manual Deployment and Policy Attachment

[dgn]

Description

Users will have to add this label for Policy Attachment to work properly.

Reviewers

• [ ] Ambient
• [ ] Docs
• [ ] Installation
• [x] Networking
• [ ] Performance and Scalability
• [ ] Extensions and Telemetry
• [ ] Security
• [ ] Test and Release
• [ ] User Experience
• [ ] Developer Infrastructure
• [ ] Localization/Translation

[istio-policy-bot]

😊 Welcome! This is either your first contribution to the Istio documentation repo, or it's been a while since you've been here. A few things you should know:

• You can learn about how we write and maintain documentation, our style guidelines, and the available web site features by visiting Contributing to the Docs.

• In the next few minutes, an automatic preview of your change will be built with a full copy of the istio.io website. You can find this preview by clicking on the Details link next to the deploy/netlify entry in the status section of this page.

• We care about quality, so we've put in place a number of checks to ensure our documentation is top-notch. We do spell checking, sanitize the Markdown, ensure all hyperlinks point to a valid location, and more. If your PR doesn't pass one of these checks, you'll see a red X in the lint_istio.io entry in the status section. Click on the Details link to get a list of the problems with your PR. Fix those problems and push an update; this will automatically re-run the tests. Hopefully this time everything will be perfect!

• Once your changes are accepted and merged into the repository, they will initially show up on https://preliminary.istio.io. The changes will be published to https://istio.io the next time we do a major release (which typically happens every 3 months or so). To publish them sooner, add a cherrypick/release-x.xx label, where x.xx is the current release of Istio.

Thanks for contributing!

Courtesy of your friendly welcome wagon.

[craigbox]

(sorry this took so long to get to)