chore(jobs): update documentation with secret_reference

Author: Gnoale

docs/resources/job_definition.md

@@ -31,6 +31,35 @@ resource scaleway_job_definition main {
 }
 ```
 
+### With Secret Reference
+
+```terraform
+resource scaleway_job_definition main {
+  name = "testjob"
+  cpu_limit = 140
+  memory_limit = 256
+  image_uri = "docker.io/alpine:latest"
+  command = "ls"
+  timeout = "10m"
+
+  cron {
+    schedule = "5 4 1 * *" # cron at 04:05 on day-of-month 1
+    timezone = "Europe/Paris"
+  }
+
+  secret_reference {
+    secret_id = "11111111-1111-1111-1111-111111111111"
+    file = "/home/dev/secret_file"
+  }
+
+  secret_reference {
+    secret_id = scaleway_secret.job_secret.id
+    secret_version = "1"
+    environment = "FOO"
+  }
+}
+```
+
 ## Argument Reference
 
 The following arguments are supported:
@@ -48,6 +77,13 @@ The following arguments are supported:
     - `timezone` - The timezone, must be a canonical TZ identifier as found in this [list](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones).
 - `region` - (Defaults to [provider](../index.md#region) `region`) The [region](../guides/regions_and_zones.md#regions) of the Job.
 - `project_id` - (Defaults to [provider](../index.md#project_id) `project_id`) The ID of the project the Job is associated with.
+- `secret_reference` - (Optional) A reference to a secret stored in [Secret Manager](../resources/secret.md).
+    - `secret_id` - (Required) The secret unique identifier, it could be formatted as region/UUID or UUID. In case the region is passed, it must be the same as the job definition. You could reference the same secret multiple times in the same job definition.
+    - `secret_version` - (Default: `latest`) The secret version.
+    - `file` - (Optional) The absolute file path where the secret will be mounted. Must be specified if `environment` is not specified.
+    - `environment` - (Optional) An environment variable containing the secret value. Must be specified if `file` is not specified.
+    - `secret_reference_id` - The secret reference UUID that is automatically generated by the provider.
+
 
 ## Attributes Reference