The parameter of some APIs are not full list.

In current API doc, the parameter is not full list for bellow API:
1.POST v2/{tenant_id}/servers/{server_id}/os-volume_attachments,
  in current document, there are 2 parameter in Parameter part:
  "tenant-id" and "server id". But it should include
  "volumeAttachment", "volumeId","device"
2.POST v2/{tenant_id}/os-networks Create a network,
  only list tenant_id in Parameter part
3. No Request Sample in POST v2/{tenant_id}/os-networks.

Fix bug 1158616

Change-Id: I66f0e29d186ea8f1bdf6a23d3cc9c0ca72db974e
Merge "The parameter of some APIs are not full list."