Update Packages array policy schema documentation

src/pages/docs/platform-hub/policies/schema.md

@@ -148,6 +148,24 @@ These two fields work together. A step that's skipped still appears in `Steps`,
 | SlugOrId | string | Yes | The slug or ID of the step or process template |
 | Version | string | No | The pinned version, if one is set |
 
+**Example usage:**
+
+```ruby
+# Check that no steps are skipped
+result := {"allowed": true} if {
+    count(input.SkippedSteps) == 0
+}
+
+# Check a specific step template is present and not skipped
+result := {"allowed": true} if {
+    some step in input.Steps
+    step.Source.Type == "Step Template"
+    step.Source.SlugOrId == "<ActionTemplate-ID>"
+    not step.Id in input.SkippedSteps
+    step.Enabled == true
+}
+```
+
 #### Packages array
 
 | Property | Type | Always Present | Description |
@@ -158,34 +176,37 @@ These two fields work together. A step that's skipped still appears in `Steps`,
 | GitRef | string | No | The Git reference for the package. Sourced from linked Build Information |
 | [Feed](#feed-object) | object | No | Details of the feed the package is sourced from |
 
-#### Feed object
-
-| Property | Type | Always Present | Description |
-| :--- | :--- | :--- | :--- |
-| Id | string | Yes | The unique identifier for the feed |
-| Name | string | Yes | Display name of the feed |
-| Slug | string | Yes | The URL-safe slug for the feed |
-| Type | string | Yes | The feed type (e.g. `BuiltIn`, `Docker`) |
-| Uri | string | No | The configured endpoint for the feed |
-
 **Example usage:**
 
 ```ruby
-# Check that no steps are skipped
+package packages_from_main_branch
+
+default result := {"allowed": false, "action": "warn"}
+
+all_packages := [pkg | some step in input.Steps; some pkg in step.Packages]
+
 result := {"allowed": true} if {
-    count(input.SkippedSteps) == 0
+    count(all_packages) == 0
 }
 
-# Check a specific step template is present and not skipped
 result := {"allowed": true} if {
-    some step in input.Steps
-    step.Source.Type == "Step Template"
-    step.Source.SlugOrId == "<ActionTemplate-ID>"
-    not step.Id in input.SkippedSteps
-    step.Enabled == true
+    count(all_packages) > 0
+    every pkg in all_packages {
+        pkg.GitRef == "refs/heads/main"
+    }
 }
 ```
 
+#### Feed object
+
+| Property | Type | Always Present | Description |
+| :--- | :--- | :--- | :--- |
+| Id | string | Yes | The unique identifier for the feed |
+| Name | string | Yes | Display name of the feed |
+| Slug | string | Yes | The URL-safe slug for the feed |
+| Type | string | Yes | The feed type (e.g. `BuiltIn`, `Docker`) |
+| Uri | string | No | The configured endpoint for the feed |
+
 :::div{.hint}
 
 See the [steps and skipping examples](/docs/platform-hub/policies/examples#check-that-a-step-isnt-skipped-in-a-deployment) for more patterns.