Volatility Spike Estimator

Plots the Average True Range (ATR), its historical mean, the upper threshold for a volatility spike, and uses background color to show the likelihood of a volatility spike based on the current ATR value.

Green background indicates an increased likelihood of a volatility spike, while red background means a spike might have already occurred or be in progress.

Update: In this version, we added a short-term ATR calculation with an adjustable input parameter, shortTermATRLength. The likelihood of a volatility spike is now estimated based on the short-term ATR instead of the original ATR. This change makes the indicator more sensitive to recent market conditions and can help detect potential volatility spikes more quickly.