API change declaration for this RFC

Signed-off-by: Woa <me@wuzy.cn>

text/0000-lifecycle-parallel-export.md

@@ -87,6 +87,40 @@ func export() {
 }
 ```
 
+## Examples
+
+For command line use, control this process through the `parallel` flag.
+
+### Export both app image and cache image
+
+By specifying environment variable `CNB_PARALLEL_EXPORT`, or pass a `-parallel` flag, images will be pushed to `cr1.example.com` and `cr2.example.com` simultaneously.
+
+```shell
+> export CNB_PARALLEL_EXPORT=true
+> /cnb/lifecycle/exporter -app cr1.example.com/foo:app -cache-image cr2.example.com/foo:cache
+
+# OR
+
+> /cnb/lifecycle/exporter -app cr1.example.com/foo:app -cache-image cr2.example.com/foo:cache -parallel
+```
+
+### Export app image only or export cache image only
+
+If export one image, the effect of this function is not very obvious.
+
+```shell
+> export CNB_PARALLEL_EXPORT=true
+> /cnb/lifecycle/exporter -app cr1.example.com/foo:app
+
+# OR
+
+> /cnb/lifecycle/exporter -app cr1.example.com/foo:app -parallel
+
+# EQUAL TO
+
+> /cnb/lifecycle/exporter -app cr1.example.com/foo:app
+```
+
 # Migration
 [migration]: #migration
 
@@ -117,7 +151,14 @@ N/A.
 # Spec. Changes (OPTIONAL)
 [spec-changes]: #spec-changes
 
-N/A.
+This new feature will affect the API of [Create](https://buildpacks.io/docs/concepts/components/lifecycle/create/) and [Export](https://buildpacks.io/docs/concepts/components/lifecycle/export/) phases, by adding the following fields.
+
+Back to API changes, we will add a new flag to control this.
+
+| Input        | Environment Variable  | DefaultValue | Description                                  |
+|--------------|-----------------------|--------------|----------------------------------------------|
+| `<parallel>` | `CNB_PARALLEL_EXPORT` | `false`      | Export app image and cache image in parallel |
+
 
 # History
 [history]: #history