add multiple terraform-docs configs to generate a seperated markdown document for input variables

Author: lonegunmanb

.terraform-docs.yml

@@ -0,0 +1,7 @@
+formatter: "markdown table" # this is required
+
+sections:
+  hide: ["inputs"]
+output:
+  file: "README.md"
+  mode: inject

.terraform-docs/README.yml

@@ -0,0 +1,7 @@
+formatter: "markdown table" # this is required
+
+sections:
+  show: ["inputs"]
+output:
+  file: "variables.md"
+  mode: inject

.terraform-docs/variables.yml

@@ -202,6 +202,8 @@ contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additio
 
 ## Module Spec
 
+Input variable spec are too big for the registry to render so we have a seperated document for these variables, check it out [here](./variables.md)
+
 The following sections are generated by [terraform-docs](https://github.com/terraform-docs/terraform-docs) and [markdown-table-formatter](https://github.com/nvuillam/markdown-table-formatter), please **DO NOT MODIFY THEM MANUALLY!**
 
 <!-- BEGIN_TF_DOCS -->