[ARROW-1804] [ Plasma C++ ] add more docs in python plasma

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Won't Fix
• Component/s: C++ - Plasma
• External issue URL: https://github.com/apache/arrow/issues/17801
• Assignee: Unassigned
• Reporter: Lu Qi
• Created: 13/Nov/17 08:37
• Updated: 11/Jan/23 07:17
• Resolved: 27/Jun/19 06:50

Description

add docs about how to get metadata in plasma client and how to use subsribe & notification
function