Documentation - basic

[anton-sidelnikov]

Summary

Add initial documentation to help users and contributors understand how to build, test, and use cloud-provider-opentelekomcloud.

Scope

Create the following documents:

• README.md – project overview, scope, and links
• docs/architecture.md – high-level architecture and design
• docs/development.md – local dev setup, build & test
• docs/usage.md – example usage with kubeadm / clusters
• CONTRIBUTING.md – contribution workflow and guidelines

Acceptance Criteria

• Clear build instructions
• Clear test instructions
• Example configuration snippets included
• Architecture and design documented