Add blog article about cgroup v2

[pacoxu]

Description

In v1.31, we announce that cgroup v1 is now in maintenance mode. Top FAQs are

1. how to migrate?
2. what's the benifits?
3. can it cover all users' usage in cgroup v1, including limitation\monitoring.

The current items include

• cgroup v1 problem, and solutions in cgroup v2
  • active_file memory is not considered as available memory
  • container aware OOM killer and better OOM handling strategies
  • rootless support
  • What's more?
• Tips to use Cgroup V2
  • requirements
  • Use systemd as cgroup driver
  • Troubleshooting Tools and Commands
• Further reading

Issue

Closes: None