feat!: Upgrade AWS provider and min required Terraform version to 6.0 and 1.5.7 respectively (#294)

* feat!: Upgrade AWS provider and min required Terraform version to `6.0` and `1.5.7` respectively

* feat: Add upgrade guide and update example

* chore: Update variable description

Author: bryantbiggs

README.md

@@ -0,0 +1,104 @@
+# Upgrade from v8.x to v9.x
+
+If you have any questions regarding this upgrade process, please consult the [`examples`](https://github.com/terraform-aws-modules/terraform-aws-autoscaling/tree/master/examples/complete) directory:
+If you find a bug, please open an issue with supporting configuration to reproduce.
+
+## List of backwards incompatible changes
+
+- Terraform v1.5.7 is now minimum supported version
+- AWS provider v6.0.0 is now minimum supported version
+
+## Additional changes
+
+### Added
+
+- Support for `region` parameter to specify the AWS region for the resources created if different from the provider region.
+
+### Modified
+
+- Variable definitions now contain detailed `object` types in place of the previously used any type.
+- `mixed_instances_policy` `override` is now wrapped behind `launch_template` to match API
+- IMDSv2 is now enforced by default with a hop limit set to 1
+
+### Variable and output changes
+
+1. Removed variables:
+
+    - `create_scaling_policy`
+    - `create_schedule`
+    - `elastic_gpu_specifications` removed in `v6.0.0` of the AWS provider
+    - `elastic_inference_accelerator` removed in `v6.0.0` of the AWS provider
+
+2. Renamed variables:
+
+    - `delete_timeout` -> `timeouts`
+
+3. Added variables:
+
+    - `autoscaling_group_tags_not_propagate_at_launch`
+    - `context`
+
+4. Removed outputs:
+
+    - None
+
+5. Renamed outputs:
+
+    - None
+
+6. Added outputs:
+
+    - None
+
+## Upgrade Migrations
+
+### Before 8.x Example
+
+```hcl
+module "asg" {
+  source  = "terraform-aws-modules/autoscaling/aws"
+  version = "~> 8.0"
+
+  # Truncated for brevity
+
+  override = [
+    {
+      instance_type     = "t3.nano"
+      weighted_capacity = "2"
+    },
+    {
+      instance_type     = "t3.medium"
+      weighted_capacity = "1"
+    },
+  ]
+  ...
+}
+```
+
+### After 9.x Example
+
+```hcl
+module "asg" {
+  source  = "terraform-aws-modules/autoscaling/aws"
+  version = "~> 9.0"
+
+  # Truncated for brevity
+  launch_template = {
+    override = [
+      {
+        instance_type     = "t3.nano"
+        weighted_capacity = "2"
+      },
+      {
+        instance_type     = "t3.medium"
+        weighted_capacity = "1"
+      },
+    ]
+  }
+  ...
+}
+```
+
+### State Changes
+
+There are no required state changes to migrate from `v8.x` to `v9.x`.

UPGRADE-4.0.md docs/UPGRADE-4.0.mdUPGRADE-4.0.md renamed to docs/UPGRADE-4.0.md

@@ -29,14 +29,14 @@ Note that this example may create resources which cost money. Run `terraform des
 
 | Name | Version |
 |------|---------|
-| <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | >= 1.3 |
-| <a name="requirement_aws"></a> [aws](#requirement\_aws) | >= 5.85, < 6.0 |
+| <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | >= 1.5.7 |
+| <a name="requirement_aws"></a> [aws](#requirement\_aws) | >= 6.0 |
 
 ## Providers
 
 | Name | Version |
 |------|---------|
-| <a name="provider_aws"></a> [aws](#provider\_aws) | >= 5.85, < 6.0 |
+| <a name="provider_aws"></a> [aws](#provider\_aws) | >= 6.0 |
 
 ## Modules
 
@@ -56,7 +56,7 @@ Note that this example may create resources which cost money. Run `terraform des
 | <a name="module_mixed_instance"></a> [mixed\_instance](#module\_mixed\_instance) | ../../ | n/a |
 | <a name="module_step_scaling_alarm"></a> [step\_scaling\_alarm](#module\_step\_scaling\_alarm) | terraform-aws-modules/cloudwatch/aws//modules/metric-alarm | ~> 4.3 |
 | <a name="module_target_tracking_customized_metrics"></a> [target\_tracking\_customized\_metrics](#module\_target\_tracking\_customized\_metrics) | ../../ | n/a |
-| <a name="module_vpc"></a> [vpc](#module\_vpc) | terraform-aws-modules/vpc/aws | ~> 5.0 |
+| <a name="module_vpc"></a> [vpc](#module\_vpc) | terraform-aws-modules/vpc/aws | ~> 6.0 |
 | <a name="module_warm_pool"></a> [warm\_pool](#module\_warm\_pool) | ../../ | n/a |
 
 ## Resources