docs(srv): add link to billing alerts to serverless FAQs MTA-6018 (#4931)

* docs(srv): add link to billing alerts to serverless FAQs MTA-6018

* Update pages/serverless-containers/faq.mdx

Co-authored-by: Néda <[email protected]>

* Update pages/serverless-functions/faq.mdx

Co-authored-by: Néda <[email protected]>

* Update pages/serverless-jobs/faq.mdx

Co-authored-by: Néda <[email protected]>

---------

Co-authored-by: Néda <[email protected]>

Author: SamyOubouaziz

pages/serverless-containers/faq.mdx

@@ -99,6 +99,10 @@ Serverless Containers are billed on a pay-as-you-go basis, strictly on resource
 
 **Monthly Cost: €22.35**
 
+<Message type="note">
+You can create billing alerts to get notifications when your costs exceed a certain threshold. Refer to the [dedicated documentation](/billing/how-to/use-billing-alerts/) for more information.
+</Message>
+
 ## Resources and performance
 
 ### Can I upgrade Serverless Container resources (vCPU and RAM) at any time?

pages/serverless-functions/faq.mdx

@@ -127,6 +127,10 @@ The scheme below illustrates our billing model:
 
 **Total monthly cost: €45.72**
 
+<Message type="note">
+You can create billing alerts to get notifications when your costs exceed a certain threshold. Refer to the [dedicated documentation](/billing/how-to/use-billing-alerts/) for more information.
+</Message>
+
 ## Resources and performance
 
 ### How to select the right resources (vCPU/RAM) for Serverless Functions ?

pages/serverless-jobs/faq.mdx

@@ -90,6 +90,10 @@ Serverless Jobs are billed on a pay-as-you-go basis, strictly on resource consum
 
 **Monthly Cost: €3,31**
 
+<Message type="note">
+You can create billing alerts to get notifications when your costs exceed a certain threshold. Refer to the [dedicated documentation](/billing/how-to/use-billing-alerts/) for more information.
+</Message>
+
 ## Resources and performance
 
 ### How do I integrate my serverless solutions with other Scaleway services?