Documentation for Sorting Billing Columns

Docs for sorting money columns in billing interface.  In ersions 2.3-2.5.

Signed-off-by: Angela Kilsdonk <akilsdonk@esilibrary.com>
Documentation for 2.5

asciidoc fix

Signed-off-by: Angela Kilsdonk <akilsdonk@esilibrary.com>