Document plan parameters for sidecar plans (#577)
Document plan parameters for sidecar plans (#577)

* Document plan parameters for sidecar plans

* Clarify that parameters are propagated to all tasks and note content-type of request

* Address comments

* Fix typo and add CLI example

* Make curl invocation consistent with rest of document

* Address comments

adragomir/dcos-commons,adragomir/dcos-commons,mesosphere/dcos-commons,mesosphere/dcos-commons,adragomir/dcos-commons,mesosphere/dcos-commons,comptelfwd/dcos-commons,comptelfwd/dcos-commons,comptelfwd/dcos-commons,mesosphere/dcos-commons,comptelfwd/dcos-commons,comptelfwd/dcos-commons,adragomir/dcos-commons,vishnu2kmohan/dcos-commons,mesosphere/dcos-commons,vishnu2kmohan/dcos-commons,vishnu2kmohan/dcos-commons,comptelfwd/dcos-commons,adragomir/dcos-commons,vishnu2kmohan/dcos-commons,vishnu2kmohan/dcos-commons