[Example] Axisymmetric initial-value problem (2D r - z plane)

[neuton]

Describe the example A finite-time pulse propagation starting from r=0 in axisymmetric cylindrical coordinates.

Additional context It's hard to figure out how to correctly setup the axisymmetric initial-value problem (2D). The present examples do include the axisymmetric case but as far as I understand are limited to the continuously-driven source of some frequency. When trying the simplest setup by manually setting p0 the simulation seems to produce unexpected results. It is not clear where the 2D grid centre is located. Neither it is clear what happens for a non-rectangular grid. A clear example showing the minimal required configuration for a successful IVP would be invaluable.