Add synergia example diagnostics output

Author: Sajid Ali

README.md

@@ -28,6 +28,9 @@ The files `example-2d.tar.gz`, `example-3d.tar.gz` and `example-thetaMode.tar.gz
 
 The scripts that were used in order to produce these openPMD files from Warp can be found in the directory `scripts/warp`.
 
+## Examples created with the Particle-In-Cell code Synergia
+The file `synergia-fodo-diag.h5` was generated by running the `fodo_cxx` example from the accelerator modeling package [`synergia`](https://github.com/fnalacceleratormodeling/synergia2) (using the `devel3` branch, commit id `81c96e4`). Is is the result of running the example file with the following command line options: `./fodo_cxx macroparticles=4096 gridx=8 gridy=8 gridz=8 turns=25` and renaming the resulting diagnostics output `diag.h5`. 
+
 ## Examples created with the finite-element code FEMM
 
 The files `example-femm-3d.h5` and `example-femm-thetaMode.h5` were produced using the finite-element code [FEMM](https://www.femm.info/wiki/HomePage).