add robots.txt

MediaBrowser.WebDashboard/MediaBrowser.WebDashboard.csproj

@@ -248,6 +248,9 @@
     <Content Include="dashboard-ui\mysyncsettings.html">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
+    <Content Include="dashboard-ui\robots.txt">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
     <Content Include="dashboard-ui\scripts\actionsheet.js">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>