Flowchart generates a Mermaid flowchart diagram from the specified [graph.Links].

Html generates a full HTML document with the Mermaid flowchart diagram.

BT is a bottom to top orientation.

LR is a left to right orientation.

RL is a right to left orientation.

TB is a top to bottom orientation.

FlowchartOptions represents the options for the flowchart diagram.

HtmlOptions represents options for the Html function.

Orientation represents the orientation of the flowchart graph.