/summon: Spawns an entity at a position, with optional rotation, spawn event and name.
Syntax
<angle brackets> are required, [square brackets] optional. /summon has 4 forms:
/summon <entityType: entitytype> [spawnPos: position_float] [yRot: rval] [xRot: rval] [spawnEvent: entityevents] [nameTag: id]
/summon <entityType: entitytype> <nameTag: id> [spawnPos: position_float]
/summon <entityType: entitytype> [spawnPos: position_float] <facing: teleportfacing> <lookAtPosition: position_float> [spawnEvent: entityevents] [nameTag: id]
/summon <entityType: entitytype> [spawnPos: position_float] <facing: teleportfacing> <lookAtEntity: selection> [spawnEvent: entityevents] [nameTag: id]