C_cpp_properties.json

{
    "version":4,
    "configurations":[
        {
            "name":"Linux",
            "includePath":[
                "${workspaceFolder}/**",
                "<nrf sdk path>",
                "<freeRTOS path>",
                "/usr/local/include",
                "/usr/include"
            ],
            "defines":[
            ],
            "compilerPath":"wherever your embedded compiler is",
            "cStandard":"c11",
            "cppStandard":"c++2a",
            "intelliSenseMode":"clang-x64"
        }
    ]
}