Minor typos in Signer configuration how to document

[jferrant]

Error in the auto deny field:
'auto_deny_addresses_stx': a list of stx addresses that should trigger an auto approve
Should be changed to:

'auto_deny_addresses_stx': a list of stx addresses that should trigger an auto deny

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.