Alpha (#4)

* chore: initial push to be able to work together

* chore: add missing wait folder

* chore: add missing folders

* chore: cleanup alpha branch

* feat: mssql alpha instance (#2)

* fix: remove unused attribute types and functions from backup models

* fix: update API client references to use sqlserverflexalpha package

* fix: update package references to use sqlserverflexalpha and modify user data source model

* fix: add sqlserverflexalpha user data source to provider

* fix: add sqlserverflexalpha user resource and update related functionality

* chore: add stackit_sqlserverflexalpha_user resource and instance_id variable

* fix: refactor sqlserverflexalpha user resource and enhance schema with status and default_database

---------

Co-authored-by: Andre Harms <andre.harms@stackit.cloud>
Co-authored-by: Marcel S. Henselin <marcel.henselin@stackit.cloud>

* feat: add sqlserver instance

* chore: fixing tests

* chore: update docs

---------

Co-authored-by: Marcel S. Henselin <marcel.henselin@stackit.cloud>
Co-authored-by: Andre Harms <andre.harms@stackit.cloud>

docs/resources/postgresflexalpha_instance.md

@@ -0,0 +1,106 @@
+---
+# generated by https://github.com/hashicorp/terraform-plugin-docs
+page_title: "stackitprivatepreview_postgresflexalpha_instance Resource - stackitprivatepreview"
+subcategory: ""
+description: |-
+  Postgres Flex instance resource schema. Must have a region specified in the provider configuration.
+---
+
+# stackitprivatepreview_postgresflexalpha_instance (Resource)
+
+Postgres Flex instance resource schema. Must have a `region` specified in the provider configuration.
+
+## Example Usage
+
+```terraform
+# Copyright (c) STACKIT
+
+resource "stackitprivatepreview_postgresflexalpha_instance" "example" {
+  project_id      = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
+  name            = "example-instance"
+  acl             = ["XXX.XXX.XXX.X/XX", "XX.XXX.XX.X/XX"]
+  backup_schedule = "00 00 * * *"
+  flavor = {
+    cpu = 2
+    ram = 4
+  }
+  replicas = 3
+  storage = {
+    class = "class"
+    size  = 5
+  }
+  version = 14
+}
+
+# Only use the import statement, if you want to import an existing postgresflex instance
+import {
+  to = stackitprivatepreview_postgresflexalpha_instance.import-example
+  id = "${var.project_id},${var.region},${var.postgres_instance_id}"
+}
+```
+
+<!-- schema generated by tfplugindocs -->
+## Schema
+
+### Required
+
+- `acl` (List of String) The Access Control List (ACL) for the PostgresFlex instance.
+- `backup_schedule` (String)
+- `encryption` (Attributes) The encryption block. (see [below for nested schema](#nestedatt--encryption))
+- `flavor` (Attributes) (see [below for nested schema](#nestedatt--flavor))
+- `name` (String) Instance name.
+- `network` (Attributes) (see [below for nested schema](#nestedatt--network))
+- `project_id` (String) STACKIT project ID to which the instance is associated.
+- `replicas` (Number)
+- `storage` (Attributes) (see [below for nested schema](#nestedatt--storage))
+- `version` (String)
+
+### Optional
+
+- `region` (String) The resource region. If not defined, the provider region is used.
+
+### Read-Only
+
+- `id` (String) Terraform's internal resource ID. It is structured as "`project_id`,`region`,`instance_id`".
+- `instance_id` (String) ID of the PostgresFlex instance.
+
+<a id="nestedatt--encryption"></a>
+### Nested Schema for `encryption`
+
+Required:
+
+- `key_id` (String) Key ID of the encryption key.
+- `key_ring_id` (String)
+- `key_version` (String)
+- `service_account` (String)
+
+
+<a id="nestedatt--flavor"></a>
+### Nested Schema for `flavor`
+
+Required:
+
+- `cpu` (Number)
+- `ram` (Number)
+
+Read-Only:
+
+- `description` (String)
+- `id` (String)
+
+
+<a id="nestedatt--network"></a>
+### Nested Schema for `network`
+
+Required:
+
+- `access_scope` (String)
+
+
+<a id="nestedatt--storage"></a>
+### Nested Schema for `storage`
+
+Required:
+
+- `class` (String)
+- `size` (Number)