Add initial API & Configuration

ObservatoryFramework/Interfaces.cs

@@ -33,11 +33,6 @@ public interface IObservatoryPlugin
     /// </summary>
     public string Version { get; }
 
-    /// <summary>
-    /// Reference to plugin UI to display within its tab.
-    /// </summary>
-    public PluginUI PluginUI { get; }
-
     /// <summary>
     /// Receives data sent by other plugins.
     /// </summary>