docs(from-context): extend documentation

website/docs/usage/load-context.md

@@ -4,14 +4,36 @@ sidebar_position: 11
 
 # Load context
 
+:::tip
+
+This is useful if you want to [print context](/docs/usage/print-context), modify it with an external tool and then "pipe" it back into **git-cliff**.
+
+:::
+
 To load a context from a file and output the generated changelog:
 
 ```bash
+# create a context
+git cliff --context -o context.json
+
+# process context and generate a changelog
+git cliff --from-context context.json
+
 # process context loaded from stdin
 git cliff --from-context -
 
-# process context loaded from a file
-git cliff --from-context context.json
+# or simply
+cat context.json | git-cliff
 ```
 
-This is useful if you want to [print context](/docs/usage/print-context), modify it with an external tool and then "pipe" it back into git cliff. Free-form metadata can be added to release objects and commit objects in the context using the `extra` field.
+Free-form metadata can be added to release objects and commit objects in the context using the `extra` field:
+
+```json
+{
+  "id": "5061081d6272b1da2146fab49d803c193db309d9",
+  "message": "commit message",
+  "extra": {
+    "note": "this is some arbitrary data"
+  }
+}
+```