(SCHEMA) Update _exist guidance for delete

This change updates guidance for resources that implement the `delete`
method to always define the `_exist` property in the JSON schema for
the resource's properties, now that DSC can automatically determine
whether to delete an instance as implemented in #382.

This change updates both the source and composed schemas.

schemas/2024/04/bundled/resource/manifest.vscode.json

@@ -638,7 +638,7 @@
                     "$id": "https://raw.githubusercontent.com/PowerShell/DSC/main/schemas/2024/04/resource/manifest.delete.json",
                     "title": "Delete method",
                     "description": "Defines how DSC must call the DSC Resource to delete an instance. Define this method for resources as an alternative to handling the `_exist` property in a `set` operation, which can lead to highly complex code. If the `set` operation for the resource is able to handle deleting an instance when `_exist` is `false`, set the `handlesExist` property of the set method definition to `true` instead.",
-                    "markdownDescription": "***\n[_Online Documentation_][01]\n***\n\nDefines how DSC must call the DSC Resource to delete an instance. Define this method for\nresources as an alternative to handling the [`_exist`][02] property in a `set` operation, which\ncan lead to highly complex code. If the `set` method for the resource is able to handle deleting\nan instance when `_exist` is `false`, set the [`handlesExist`][03] property of the set method\ndefinition to `true` instead.\n\n[01]: https://learn.microsoft.com/powershell/dsc/reference/schemas/resource/manifest/delete?view=dsc-3.0&preserve-view=true\n[02]: https://learn.microsoft.com/powershell/dsc/reference/schemas/resource/properties/exist?view=dsc-3.0&preserve-view=true\n[03]: https://learn.microsoft.com/powershell/dsc/reference/schemas/resource/manifest/set?view=dsc-3.0&preserve-view=true#handlesExist\n",
+                    "markdownDescription": "***\n[_Online Documentation_][01]\n***\n\nDefines how DSC must call the DSC Resource to delete an instance. Define this method for\nresources as an alternative to handling the [`_exist`][02] property in a `set` operation, which\ncan lead to highly complex code. If the `set` method for the resource is able to handle deleting\nan instance when `_exist` is `false`, set the [`handlesExist`][03] property of the set method\ndefinition to `true` instead.\n\nIf you define the delete method in a resource manifest, ensure that you also define the\n[`_exist`][02] property in the [JSON schema for the resource's properties][04].\n\n[01]: https://learn.microsoft.com/powershell/dsc/reference/schemas/resource/manifest/delete?view=dsc-3.0&preserve-view=true\n[02]: https://learn.microsoft.com/powershell/dsc/reference/schemas/resource/properties/exist?view=dsc-3.0&preserve-view=true\n[03]: https://learn.microsoft.com/powershell/dsc/reference/schemas/resource/manifest/set?view=dsc-3.0&preserve-view=true#handlesExist\n[04]: https://learn.microsoft.com/powershell/dsc/reference/schemas/resource/manifest/schema/property?view=dsc-3.0&preserve-view=true\n",
                     "type": "object",
                     "required": [
                       "executable",

schemas/src/resource/manifest.delete.yaml

@@ -21,9 +21,13 @@ markdownDescription: | # VS Code only
   an instance when `_exist` is `false`, set the [`handlesExist`][03] property of the set method
   definition to `true` instead.
 
+  If you define the delete method in a resource manifest, ensure that you also define the
+  [`_exist`][02] property in the [JSON schema for the resource's properties][04].
+
   [01]: <DOCS_BASE_URL>/reference/schemas/resource/manifest/delete?<DOCS_VERSION_PIN>
   [02]: <DOCS_BASE_URL>/reference/schemas/resource/properties/exist?<DOCS_VERSION_PIN>
   [03]: <DOCS_BASE_URL>/reference/schemas/resource/manifest/set?<DOCS_VERSION_PIN>#handlesExist
+  [04]: <DOCS_BASE_URL>/reference/schemas/resource/manifest/schema/property?<DOCS_VERSION_PIN>
 
 type: object
 required:

schemas/src/resource/properties/exist.yaml

@@ -16,9 +16,13 @@ markdownDescription: |
   [_Online Documentation_][01]
   ***
 
-  Indicates whether the DSC Resource instance should exist.
+  Indicates whether the DSC Resource instance should exist. For DSC Resources that define the
+  [delete method in their manifest][02], DSC calls the `delete` method for the resource when an
+  instance defines `_exist` as `false` and the instance exists.
+
 
   [01]: <DOCS_BASE_URL>/reference/schemas/resource/properties/exist?<DOCS_VERSION_PIN>
+  [02]: <DOCS?BASE_URL>/reference/schemas/resource/manifest/delete?<DOCS_VERSION_PIN>
 markdownEnumDescriptions:
   - | # false
     _Instance shouldn't exist._