fix: Build documentation at compilation

Some documentation was broken. I refactored it to be declarative now the
project build correctly and produce XML documentation.

WhiteMagic/Windows/RemoteWindow.cs

@@ -113,6 +113,7 @@ public sealed class RemoteWindow
         return NativeMethods.FlashWindowEx(ref info);
     }
 
+    /// <summary>Returns a string representation of this window, including its handle, class name, and title.</summary>
     public override string ToString()
     {
         var sb = new StringBuilder();