Clarify terraform serverless support (#3934)

## Description

Terraform is supposed to be supported on serverless

To address below issues:
* [Issue 1](elastic/support-tech-lead#1673)
* [Issue 2](elastic/docs-content-internal#443)
* [Issue 3](https://support.elastic.dev/knowledge/view/57137a36)

## Preview - before merge

[deploy-manage/deploy/elastic-cloud/tools-apis.md](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/3934/deploy-manage/deploy/elastic-cloud/tools-apis)

## Preview - after merge


https://www.elastic.co/docs/deploy-manage/deploy/elastic-cloud/tools-apis#provision-deployments-with-terraform

cc @maggieghamry @ppf2

---------

Co-authored-by: Vlada Chirmicci <[email protected]>

Author: kunisen

deploy-manage/deploy/_snippets/tpec.md

@@ -1,3 +1,3 @@
-The {{ecloud}} Terraform provider allows you to provision and manage {{ech}} and {{ece}} deployments as code, and introduce DevOps-driven methodologies to manage and deploy the {{stack}} and solutions.
+The {{ecloud}} Terraform provider allows you to provision and manage {{serverless-full}} projects, {{ech}} and {{ece}} deployments as code, and introduce DevOps-driven methodologies to manage and deploy the {{stack}} and solutions.
 
-To get started, see the [{{ecloud}} Terraform provider documentation](https://registry.terraform.io/providers/elastic/ec/latest/docs).
+To get started, review the [{{ecloud}} Terraform provider documentation](https://registry.terraform.io/providers/elastic/ec/latest/docs) and [{{ecloud}} Terraform GitHub repository](https://github.com/elastic/terraform-provider-ec) for more guidance.

deploy-manage/deploy/elastic-cloud/tools-apis.md

@@ -96,12 +96,7 @@ serverless: unavailable
 :::
 
 
-## Provision deployments with Terraform
-```{applies_to}
-deployment:
-  ess: ga
-serverless: unavailable
-```
+## Provision projects and deployments with Terraform
 
 :::{include} /deploy-manage/deploy/_snippets/tpec.md
 :::