Implemented dynamic rows feature #2

Added the ability to render dynamic rows to an already rendered table. This functionality is exposed via a new method `RenderDynamic()` which only renders the new rows of the table to the end of the currently rendered table.

There is one trick however used in this implementation, if `UseSeparator = true` then when calling `RenderDynamic()` it will overwrite the last written line in the terminal, this is to create a seamless rendered table.