Add note to 3D field docs about unsupported WPILib types

docs/tabs/3D-FIELD.md

@@ -48,6 +48,10 @@ Logger.recordOutput("MyPoseArray", poseA, poseB);
 Logger.recordOutput("MyPoseArray", new Pose3d[] {poseA, poseB});
 ```
 
+> Note: Without AdvantageKit, WPILib does not currently support structured logging of trajectories (as of 2024.1.1-beta-2). Keep an eye out for updates on this feature. In the meantime, trajectories can be logged using `Field2d` or as an array of poses.
+
+WPILib's [`Field2d`](https://docs.wpilib.org/en/stable/docs/software/dashboards/glass/field2d-widget.html) class can also be used to log several sets of 2D pose data together.
+
 ### Legacy Format
 
 Alternatively, pose data can be stored as a numeric array describing one or more poses with the formats shown below.