[Docs]: Please add links to pgBackRest-based backup plugins

[bmironov]

Is there an existing issue already for your request/idea?

• I have searched for an existing issue, and could not find anything. I believe this is a new documentation enhancement to be evaluated.

What problem in the existing documentation this issue aims to solve?

There are few more CNPG-I base plugins in the world besides Barman Cloud

Describe what additions need to be done to the documentation

Could you please add two CNPG-I plugins which are based on pgbackrest tool list in main README.md?

They are from:

• Opera Software
• Dalibo

Describe what pages need to change in the documentation, if any

Main README.md in section about available CNPG-I plugins

Describe what pages need to be removed from the documentation, if any

No response

Additional context

No response

Backport?

Yes

Code of Conduct

• I agree to follow this project's Code of Conduct