docs: add tabs WIP

[petermakowski]

Done

• docs: add tabs WIP

QA

• Click on the "UI" tab and verify that only the UI-specific content is visible.
• Click on the "CLI" tab and verify that only the CLI-specific content is visible.
• Toggle between the tabs multiple times to ensure the content is consistently shown/hidden based on the selected tab.
• Open the docs page, e.g. docs/how-to-set-up-maas and verify that the UI is set in the URL
• Copy the URL of the page with the "UI" tab selected, paste it into a new browser tab, and verify that the "UI" tab is selected and the UI content is visible.
• Select the "CLI" tab and refresh the page. Verify that the "CLI" tab remains selected and the CLI content is visible.
• Click on a navigation item on the left to navigate to another docs page and verify that it still has "CLI" selected

Issue / Card

Screenshots