Dissolution of marriage — Child custody — Modification — Change in circumstances — Domestic violence — No error modifying timesharing of parties’ minor child — Competent, substantial evidence supported trial court’s finding that there was a substantial change in circumstances based upon unforeseen and disturbing incidents of domestic violence between former husband and his current wife — Although record did not support factual findings that minor child hid and called 911 during one incident or that incidents were fueled by alcohol, former husband and current wife’s testimony provided ample support for determination that former husband had exposed child to domestic violence and tried to conceal the incident from former wife by telling child to keep the matter a secret — Sole parental responsibility — Education — Error to award sole responsibility for child’s education to former wife where there was no finding that shared parental responsibility was detrimental to child