Add terraform_ordered_locals to the doc index (#32)

Author: wata727

docs/rules/README.md

@@ -15,6 +15,7 @@ All rules are enabled by default, but by setting `preset = "recommended"`, you c
 |[terraform_module_pinned_source](terraform_module_pinned_source.md)|Disallow specifying a git or mercurial repository as a module source without pinning to a version|✔|
 |[terraform_module_version](terraform_module_version.md)|Checks that Terraform modules sourced from a registry specify a version|✔|
 |[terraform_naming_convention](terraform_naming_convention.md)|Enforces naming conventions for resources, data sources, etc||
+|[terraform_ordered_locals](terraform_ordered_locals.md)|Recommend proper order for variables in `locals` blocks||
 |[terraform_required_providers](terraform_required_providers.md)|Require that all providers have version constraints through required_providers|✔|
 |[terraform_required_version](terraform_required_version.md)|Disallow `terraform` declarations without require_version|✔|
 |[terraform_standard_module_structure](terraform_standard_module_structure.md)|Ensure that a module complies with the Terraform Standard Module Structure||