Please add an option to download/install terraform

**Describe the solution you'd like**
I would like to be able to use `terraform-fmt` on [pre-commit.ci](https://pre-commit.ci/), the hosted CI pre-commit service, but unfortunately I cannot because `terraform` doesn't come pre-installed, and the hooks here do not install/bundle it.

```
Terraform fmt............................................................Failed
- hook id: terraform-fmt
- exit code: 127

/pc/clone/RKgVfIZxQCiSAX665qKF9Q/hooks/terraform-fmt.sh: line 15: terraform: command not found
```

It'd be nice if there was a way to say that you need terraform installed as part of the hook.

**Describe alternatives you've considered**
Not running terraform hooks on pre-commit.ci.