Exclude Content from Nuget

I am creating a nuget and want to exclude everything from the contentFiles/Content while creating nuget. I am just using the .csproj files.

I tried few things like these, but it still creates the contentFiles.

<PropertyGroup><DefaultItemExcludes>$(DefaultItemExcludes);**/*.proto</DefaultItemExcludes></PropertyGroup>

Also tried

<PropertyGroup><DefaultItemExcludes>$(DefaultItemExcludes);**/*.proto</DefaultItemExcludes></PropertyGroup>

Can someone help me out.