Missing include flag -I/usr/include/tidy in pkg-config tidy.pc file

Hello, I'm not sure where to report this issue as it is related to the tidy-html5 package and its pkg-config .pc file.

When using pkg-config to get tidy library CFLAGS:

pkg-config --cflags tidy

There is only the default include directory (/usr/include) however tidy headers are located in the /usr/include/tidy so there should also be the -I/usr/include/tidy flag given in there. https://salsa.debian.org/debian/tidy-html5/-/blob/debian/latest/debian/libtidy-dev.install

Probably the INCLUDE_INSTALL_DIR variable needs to be set in the CMake installation somewhere.

The tidy-html5 headers are meant to be included like this according to the documentation <tidy.h> https://api.html-tidy.org/tidy/tidylib_api_5.8.0/libtidy_04.html

Thank you.