chore: Add initial upgrade guide to capture changes

Author: bryantbiggs

docs/UPGRADE-10.0.md

@@ -0,0 +1,87 @@
+# Upgrade from v9.x to v10.x
+
+If you have any questions regarding this upgrade process, please consult the `examples` directory.
+If you find a bug, please open an issue with supporting configuration to reproduce.
+
+## List of backwards incompatible changes
+
+- Terraform `v1.11` is now minimum supported version to support write-only (`wo_*`) attributes.
+- AWS provider `v6.18` is now minimum supported version
+- The underlying `aws_security_group_rule` resources has been replaced with `aws_vpc_security_group_ingress_rule` and `aws_vpc_security_group_egress_rule` to allow for more flexibility in defining security group rules.
+
+## Additional changes
+
+### Added
+
+- Support for `region` argument 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
+
+### Removed
+
+- None
+
+### Variable and output changes
+
+1. Removed variables:
+
+    -
+
+2. Renamed variables:
+
+    -
+
+3. Added variables:
+
+    -
+
+4. Removed outputs:
+
+    -
+
+5. Renamed outputs:
+
+    -
+
+6. Added outputs:
+
+    -
+
+## Upgrade Migrations
+
+### Before 9.x Example
+
+```hcl
+module "cluster" {
+  source  = "terraform-aws-modules/rds-aurora/aws"
+  version = "~> 9.0"
+
+  # Only the affected attributes are shown
+
+
+  tags = {
+    Environment = "dev"
+    Terraform   = "true"
+  }
+}
+```
+
+### After 10.x Example
+
+```hcl
+module "cluster" {
+  source  = "terraform-aws-modules/rds-aurora/aws"
+  version = "~> 10.0"
+
+  # Only the affected attributes are shown
+
+  tags = {
+    Environment = "dev"
+    Terraform   = "true"
+  }
+}
+```
+
+### State Changes