feat(inference): update faq with billing per minute (#5063)

Author: fpagny

pages/managed-inference/faq.mdx

@@ -57,7 +57,7 @@ Managed Inference offers different Instance types optimized for various workload
 You can select the Instance type based on your model’s computational needs and compatibility.
 
 ## How is Managed Inference billed?
-Billing is based on the Instance type and usage duration. Unlike [Generative APIs](/generative-apis/quickstart/), which are billed per token, Managed Inference provides predictable costs based on the allocated infrastructure.
+Billing is based on the Instance type and usage duration (in minutes). Unlike [Generative APIs](/generative-apis/quickstart/), which are billed per token, Managed Inference provides predictable costs based on the allocated infrastructure. Billing only starts when model a deployment is ready and can be queried.
 Pricing details can be found on the [Scaleway pricing page](https://www.scaleway.com/en/pricing/model-as-a-service/#managed-inference).
 
 ## Can I pause Managed Inference billing when the instance is not in use?
@@ -79,4 +79,4 @@ Absolutely. Managed Inference integrates seamlessly with other Scaleway services
 ## Do model licenses apply when using Managed Inference?
 Yes, model licenses need to be complied with when using Managed Inference. Applicable licenses are available for [each model in our documentation](/managed-inference/reference-content/).
 - For models provided in the Scaleway catalog, you need to accept licenses (including potential EULA) before creating any Managed Inference deployment.
-- For custom models you choose to import on Scaleway, you are responsible for complying with model licenses (as with any software you choose to install on a GPU Instance for example).
+- For custom models you choose to import on Scaleway, you are responsible for complying with model licenses (as with any software you choose to install on a GPU Instance for example).