Fix README.md not getting included

Author: harry-cpp

Resources/MonoGame.Tool.X.txt

@@ -12,7 +12,7 @@
 
   <ItemGroup>
       <None Include="../{LicensePath}" Pack="true" PackagePath="" />
-      <None Include="../README.md" Pack="true" PackagePath="" />
+      <None Include="README.md" Pack="true" PackagePath="" />
       <None Include="Icon.png" Pack="true" PackagePath="" />
   </ItemGroup>