Updated the 'Create and manage containers' section

Included the following changes:
- Option to make container Public or Private
- New section 'Manage an object' with procedures to:
  * Edit an object
  * Copy an object from one container to another
  * Create a metadata-only object without a file
  * Create a pseudo-folder
Partial-Bug: #1307860

Change-Id: I3651abae223b4891f890ecf036c699add3ef3687
Merge "Updated the 'Create and manage containers' section"