Add a note to docs about having access to saved object management table

[bhavyarm]

Kibana version: 7.11.0 BC4

Describe the bug: If user has all access privileges to saved object management table - they have access to all the saved object types. So even if they don't have access to Tag Management or Index pattern management - they can delete tag saved objects or index patterns from saved object management table. This works as expected but It will be a good to add a note here https://www.elastic.co/guide/en/kibana/current/kibana-role-management.html.

[legrego]

@bhavyarm we have a note for this already at https://www.elastic.co/guide/en/kibana/7.x/managing-saved-objects.html (via #80486), which added:

[bhavyarm]

Oh sweet. Thanks @legrego