Biot-Savart volume integral

CHANGELOG.md

@@ -87,6 +87,7 @@ New Features
 - Adds the classes ``FourierXYCurve`` and ``FourierXYCoil`` to represent planar curves/coils with Fourier series for X and Y instead of the radius.
 - Removes default objective and constraints for ``desc.equilibrium.Equilibrium.optimize``, so now user is required to pass in the constraints and objective when using this method.
 - Adds ``PlasmaCoilSetDistanceBound`` objective to allow a simultaneous constraint on minimum and maximum distance between the plasma and coils.
+- Adds ``grid.meshgrid_flatten`` for flattening 3d data to a 1d array in the correct order.
 - Adds `desc.plotting.plot_field_lines` function, which integrates and then plots magnetic field line trajectories in 3D.
 - `desc.magnetic_fields.field_line_integrate` now integrates the field line always in the given `phis` direction, and `phis` will always correspond to the physical toroidal angle (instead of time like coordinate previously). Previous implementation might have caused confusion about the output positions, especially when the magnetic field has negative toroidal component.
 - Adds ``grid.meshgrid_flatten`` for flattening 3d data to a 1d array in the correct order.