add references to "libpjproject" and "pjsua2_lib"

[dv8inpp]

Hi Aaron, thanks for the work you've done here and the documentation. Your instructions are very good but I'm having trouble with this bit.

Do you mean the lib files such as "libpjproject-i386-Win32-vc14-Release.lib" and "pjsua2-lib-i386-Win32-vc14-Release.lib" or something else?

I've created the VS 2019 DLL project as specified but am unable to add any references to it.