Implemented Tom Demark Sequential Indicator in QuantConnect

Contributed to [QuantConnect’s LEAN](https://www.twine.net/signin open-source quantitative trading engine by implementing the Tom Demark’s Sequential candlestick indicator used for trend reversal detection. This feature adds support for detecting trend exhaustion and potential reversals, increasing the toolkit available to quantitative strategy developers. Implemented the indicator with full support for Setup/Countdown phases and price flip logic. Demonstrated proficiency in C#, Git, unit testing, and financial modelling with a focus on clean code and extensibility.