Added paragraph about siteaccess scopes are merged

[vidarl]

Question	Answer
JIRA Ticket	N/A
Versions	3.3, 4.6
Edition	Content/Headless,

Added paragraph about settings for the different siteaccess scopes are merged

Checklist

• [ ] Text renders correctly
• [ ] Text has been checked with vale
• [ ] Description metadata is up to date
• [ ] Redirects cover removed/moved pages
• [ ] Code samples are working
• [ ] PHP code samples have been fixed with PHP CS fixer
• [ ] Added link to this PR in relevant JIRA ticket or code PR