[CCV] WIP - Update Azure docs

[crousseaux]

What does this PR do? What is the motivation?

CCM now support creating Azure exports using the improved experience. We are updating the docs to reflect this.

New tabs:

Merge instructions

• [ ] Please merge after reviewing ⚠️ Do not merge yet

[github-actions[bot]]

Preview links (active after the build_preview check completes)

Modified Files

• https://docs-staging.datadoghq.com/constance/update-azure-docs/cloud_cost_management/azure

[crousseaux]

Alternatively, we could have something like this instead of the tabs. But I thought it was too confusing.

[goeln]

Thanks for putting this together! A few suggestions:

1. Right below the tab for Regular vs Improved exports, can we add a short note that Improved exports are in Preview and link to the docs? Something like: "The Azure improved exports experience (https://learn.microsoft.com/en-us/azure/cost-management-billing/costs/tutorial-improved-exports) is in Preview and may not be available for all customers"

2. Should we make the tabs for Regular exports vs Improved exports be at the top? Even though steps 1-3 are the same regardless, it might make it more natural to add the links

[crousseaux]

@goeln unfortunately links don't work in tabs :/ so kept the old format