docs: update seo plugin tabbedUI docs to mention potential pitfalls with the config option (#12549)

Closes #12355

TabbedUI doesn't always work as intended and it can be affected by
existing fields or the order of other plugins, this mentions that and
links to the recommended direct use of fields example.

Author: paulpopus

docs/plugins/seo.mdx

@@ -115,6 +115,7 @@ Set the `uploadsCollection` to your application's upload-enabled collection slug
 ##### `tabbedUI`
 
 When the `tabbedUI` property is `true`, it appends an `SEO` tab onto your config using Payload's [Tabs Field](../fields/tabs). If your collection is not already tab-enabled, meaning the first field in your config is not of type `tabs`, then one will be created for you called `Content`. Defaults to `false`.
+Note that the order of plugins or fields in your config may affect whether or not the plugin can smartly merge tabs with your existing fields. If you have a complex structure we recommend you [make use of the fields directly](#direct-use-of-fields) instead of relying on this config option.
 
 <Banner type="info">
   If you wish to continue to use top-level or sidebar fields with `tabbedUI`,