Feature Request: renko with specific starting price value

In the current version the renko bricks are calculated from the beginning of the dataframe.
Calling the plot later with updated dataframe the bricks' calculation results in different chart.

It would be great to have a set starting/turning value point in pips, multipules of minimal tick movements, fraction of 1point or set at/by the bricksize value.

Start by locating the Renko calculation and plotting entry points in mplfinance; no specific files or tests are named in the issue. Define how a starting or turning value should be supplied, including pip, tick, fractional-point, and brick-size options, then verify that recalculating with an updated dataframe preserves the intended chart.

Written by the indexing model from the issue text.