Add or review documentation for the Billing page

[Freddyminu]

Overview

Ensure the Billing page has complete and accurate documentation.

Tasks

• Check if a Billing page already exists in the docs
  • If it does not exist: create a new documentation page for Billing — only start once QA has approved the Billing page
  • If it already exists: review the page and identify any missing or outdated information, then update accordingly

What the Billing docs should cover (at minimum)

• Overview of the Billing page and where to find it
• How to view current plan and usage
• How to upgrade or change plans
• Payment methods and invoices
• Any relevant limits or quotas tied to billing tiers

Additional context

• Do not begin writing new docs until QA sign-off on the Billing page is confirmed
• If the page already exists, a gap analysis against the current Billing UI is sufficient to start

[Freddyminu]

https://docs.tago.io/docs/tagoio/my-account/billing/setup-billing

Note: There's a typo in the link of the billing page

[Freddyminu]

Issue requested by @vitorfdl