add doc for external shock test
add doc for external shock test

MG-RAST/Shock,wgerlach/Shock,wgerlach/Shock,wgerlach/Shock,wgerlach/Shock,MG-RAST/Shock,MG-RAST/Shock,wgerlach/Shock,MG-RAST/Shock,MG-RAST/Shock