refactor: update webhooks variable type and usage (#22)

- Changed the type of `webhooks` variable from `list` to `map` in `variables.tf` and `README.md`.
- Updated the default value of `webhooks` variable from `[]` to `{}`.
- Modified the `for_each` expression in `github_repository_webhook` resource in `main.tf` to iterate over the map of webhooks.

Author: erikreinert

README.md

@@ -72,7 +72,7 @@ No modules.
 | <a name="input_topics"></a> [topics](#input\_topics) | The topics of the repository | `list(string)` | `[]` | no |
 | <a name="input_visibility"></a> [visibility](#input\_visibility) | The visibility of the repository | `string` | `"private"` | no |
 | <a name="input_vulnerability_alerts"></a> [vulnerability\_alerts](#input\_vulnerability\_alerts) | Whether the repository has vulnerability alerts enabled | `bool` | `false` | no |
-| <a name="input_webhooks"></a> [webhooks](#input\_webhooks) | The URLs of the webhooks | <pre>list(object({<br>    active       = bool<br>    events       = list(string)<br>    content_type = string<br>    url          = string<br>  }))</pre> | `[]` | no |
+| <a name="input_webhooks"></a> [webhooks](#input\_webhooks) | Webhooks to configure for the repository | <pre>map(object({<br>    active       = bool<br>    events       = list(string)<br>    content_type = string<br>    url          = string<br>  }))</pre> | `{}` | no |
 
 ## Outputs
 

main.tf

@@ -66,7 +66,7 @@ resource "github_branch_protection" "self" {
 }
 
 resource "github_repository_webhook" "self" {
-  for_each = toset(var.webhooks)
+  for_each = { for webhook_key, webhook in var.webhooks : webhook_key => webhook }
 
   active     = each.value.active
   events     = each.value.events

variables.tf

@@ -182,9 +182,9 @@ variable "vulnerability_alerts" {
 }
 
 variable "webhooks" {
-  default     = []
-  description = "The URLs of the webhooks"
-  type = list(object({
+  default     = {}
+  description = "Webhooks to configure for the repository"
+  type = map(object({
     active       = bool
     events       = list(string)
     content_type = string