Add 3+ months as a duration option in the search filter

Hello World, first let me thank the THS Dev team for all the improvements the website has seen in the past year.

As the title says the slider for the duration of the sit, in the search filters, is 1+ months or 6+ months and I believe that is too much of a gap. When I am looking for 3+ months I have to manually check one by one. So adding another option in the slider for 3+ will be ideal.

Best regards,