Eighteen-year-old Richards made his first-team debut for the Stones towards the end of last season.
He joined the club at the age of 12 and was part of one of the most successful youth sides in recent years.
In September 2015, he started at the Stones football academy and won back-to-back National League Youth Alliance championships.
He spent from October 20th until November 11th on loan at National League South neighbours Welling United and has also played seven times in the Stones` senior side this season.