This is probably a good place to start. It shows how to create HDMI out on the Pynq-Z2 but the principal should apply to any Zynq board with a HDMI output.
Along with the above, have you seen the resources that are listed on the ZedBoard product page?
There is a design there showing how to use the HDMI. You can leverage that to do what you are asking.
You can also investigate support that Digilent offers at their forums for newer versions of designs. Lastly, there are other boards that have more support around them, which also uses the same HDMI circuit, such as PicoZed with FMCv2. However, you are on your own with any software porting you do.