Add "noIndex" property to /0.11/ versioned docs (#53)

The "noIndex" property here adds `<meta name="robots" content="noindex,
nofollow">` to all `/0.11/` pages, instructing search engines not to
index or follow links on outdated documentation.

https://docusaurus.io/docs/api/docusaurus-config#noIndex

Author: Xenc5

docusaurus.config.ts

@@ -86,6 +86,9 @@ const config: Config = {
             [LATEST_DEVVIT_VERSION]: {
               badge: false,
             },
+            "0.11": {
+              noIndex: true,
+            },
           },
         },
         blog: {