Landing page on a public URL with docs (other than Marketplace)

[kingdonb]

We have this landing page: https://marketplace.visualstudio.com/items?itemName=Weaveworks.vscode-gitops-tools

But we should have a different page that we can use for hosting docs. Put them on a GitHub Pages site where we can direct people to go read our docs, the Beginners/Getting Started for New To Flux and New To GitOps, vs Seasoned Flux Users page, etc. All of our docs should be hosted there and navigable. It should have a single "funnel/call-to-action" page where the Gif that demonstrates how to use VSCode Extension in order to achieve basic GitOps is hosted.

I'm skeptical that we can get any navigation or tabbed elements to work in our webview as when I first tested it, rendering was great but links all did not work; but if we enable JavaScript I think it's possible to do some single-page navigation. I would like for the beginner docs page to have an easy callout that directs users to the more advanced docs, in case the "GitOps Is Easy" copy doesn't provide them with the depth of information they're looking for.

We should have more advanced docs that call out to the Flux docs in roughly the order that we think users will need to learn about Flux features. That is all out of scope for this, but a "More VSCode/Flux Docs Coming Soon Here - Watch This Space" could be in scope if it looks nice and doesn't detract too much.

• [X] Adding the word fluxcd to the repo ~as mentioned in https://github.com/weaveworks/vscode-gitops-tools/pull/296#issuecomment-1165575609 will make this link appear on the extension marketplace landing~ this is done 👍

[kingdonb]

~To go with this, the fluxcd keyword returns no results, we have information in https://github.com/weaveworks/vscode-gitops-tools/pull/298#issuecomment-1165572613 about where we should add it to make sure the search returns our ext.~ done

[kingdonb]

As a follow-up to #319 we need to build a workflow that publishes the new doc to a GitHub Pages target on release. No need to preserve historical versions for now, we'll hopefully only need one version of this page and we can iterate on it additively.