Feature request or question: How can I pass shared parameter in each environment

### Describe your idea/feature/enhancement

Is there a way to share the parameters?
I want a global section for each environment.

like
```toml
version=0.1
[global]
s3_bucket = "my-source-bucket"
region = "us-west-2"

[dev.deploy.parameters]
stack_name = "my-app-stack-dev"
s3_prefix = "my-s3-prefix-dev"

[prod.deploy.parameters]
stack_name = "my-app-stack-prod"
s3_prefix = "my-s3-prefix-prod"

```

this means like below

```toml
version=0.1

[dev.deploy.parameters]
stack_name = "my-app-stack-dev"
s3_prefix = "my-s3-prefix-dev"
s3_bucket = "my-source-bucket"
region = "us-west-2"

[prod.deploy.parameters]
stack_name = "my-app-stack-prod"
s3_prefix = "my-s3-prefix-prod"
s3_bucket = "my-source-bucket"
region = "us-west-2"
```