Sort listings by:
- sortprice - sort by listing price, in descending order. This is the default.
- sortpriceasc - sort by listing price in ascending order.
- sortcity - sort by city
- sortsqft - sort by square footage of property (if available)
- sortacres - sort by acres (if available)
- sortbedrooms - sort by bedrooms
- sortpricepersqft - sort by price per sqaure foot.
- sortnewest - sort by newest listings first
- sortsold - sort by sold date
- rand - display listings in random order
For rover_idx_testimonials, sort_by supports `rand` only.