website/docs: added a Docs banner to announce new docs structure (#11525)

* banner on Docs

* color fun

* tweak length of message, color

* add real deploy url

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Co-authored-by: Tana M Berry <tana@goauthentik.com>

website/docusaurus.config.ts

@@ -17,6 +17,14 @@ module.exports = async function (): Promise<Config> {
         organizationName: "Authentik Security Inc.",
         projectName: "authentik",
         themeConfig: {
+            announcementBar: {
+                id: "new_docs_structure",
+                content:
+                    'Change is hard, especially when a familiar site gets re-arranged. But we think the new layout is easier to navigate. Take a preview peek at the upcoming new <a target="_blank" rel="noopener noreferrer" href="https://deploy-preview-11522--authentik-docs.netlify.app/docs"> Docs structure!</a>',
+                backgroundColor: "#cc0099",
+                textColor: "#ffffff",
+                isCloseable: false,
+            },
             image: "img/social.png",
             navbar: {
                 logo: {