Ethernet Webserver How to use separate HTML file instead of inline

Im using a Raspberry pico Rp2040 Board. Im planning on storing it in flash Actually Since the pico has a lot of flash space compared to other boards(2Mb).

I was actually thinking of doing this incase there was no other way of doing it. I would include some sort of .h file that is generated by the script.

its kind of a shame the library do not have inbuilt support for it.