This procedure is used to render the page header. It is automatically called by AddPage and
should not be called directly by the application. The implementation in TclFPDF is empty, so
you have to override the procedure if you want a specific processing.
Example
proc Header {} {
# Select Arial bold 15
SetFont Arial B 15;
# Move to the right
Cell 80;
# Framed title
Cell 30 10 "Title" 1 0 C;
# Line break
Ln 20;
}