add more to .net core solution

MediaBrowser.WebDashboard.nuget.targets

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8" standalone="no"?>
+<Project ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Target Name="EmitMSBuildWarning" BeforeTargets="Build">
+    <Warning Text="Packages containing MSBuild targets and props files cannot be fully installed in projects targeting multiple frameworks. The MSBuild targets and props files have been ignored." />
+  </Target>
+</Project>

project.json

@@ -1,7 +1,17 @@
 {
-  "supports": {},
-  "dependencies": {},
-  "frameworks": {
-    ".NETPortable,Version=v4.5,Profile=Profile7": {}
+    "frameworks":{
+        "netstandard1.6":{
+           "dependencies":{
+                "NETStandard.Library":"1.6.0",
+            }
+        },
+        ".NETPortable,Version=v4.5,Profile=Profile7":{
+            "buildOptions": {
+                "define": [  ]
+            },
+            "frameworkAssemblies":{
+                
+            }
+        }
     }
 }