Update Portal UI Documentation URL

[SergK]

Is your feature request related to a problem? Please describe.
The current EDP Headlamp documentation needs to be updated to reflect the new URL. The existing documentation currently points to an outdated URL, and this task involves updating all references within the documentation to the new URL: https://docs.kuberocketci.io.

Describe the solution you'd like

1. All references to the old EDP Headlamp documentation URL within the project's documentation are identified.
2. Each reference is updated to the new URL: https://docs.kuberocketci.io.
3. No broken links are present in the documentation after the update.
4. The documentation is reviewed to ensure all updates are correct and functional.
5. Changes are merged into the main branch without conflicts.

Also replace https://github.com/epam/edp-install/discussions with https://github.com/KubeRocketCI/docs/discussions

Additional context
Implementing this change will ensure that users are directed to the correct and current documentation, enhancing the user experience and maintaining the integrity of the project's documentation resources.