docs: Add example run for the download command

docs/codegen/download_schemas.md

@@ -1,8 +1,28 @@
 # Download Schemas
 
 Generating from remote resources is not a great idea, the cli includes a command to
-download schemas and wsdl locally.
+download schemas and wsdl locally. The command will download any included schemas
+recursively.
 
 ```console exec="1" source="console"
 $ xsdata download --help
 ```
+
+**Example**
+
+```console
+❯ xsdata download https://www.w3.org/Math/XMLSchema/mathml3/mathml3.xsd -o ~/schemas
+========= xsdata v24.6.1 / Python 3.11.8 / Platform linux =========
+
+Setting base path to https:/www.w3.org/Math/XMLSchema/mathml3
+Fetching https://www.w3.org/Math/XMLSchema/mathml3/mathml3.xsd
+Fetching https://www.w3.org/Math/XMLSchema/mathml3/mathml3-content.xsd
+Fetching https://www.w3.org/Math/XMLSchema/mathml3/mathml3-strict-content.xsd
+Writing /home/chris/schemas/mathml3-strict-content.xsd
+Writing /home/chris/schemas/mathml3-content.xsd
+Fetching https://www.w3.org/Math/XMLSchema/mathml3/mathml3-presentation.xsd
+Writing /home/chris/schemas/mathml3-presentation.xsd
+Fetching https://www.w3.org/Math/XMLSchema/mathml3/mathml3-common.xsd
+Writing /home/chris/schemas/mathml3-common.xsd
+Writing /home/chris/schemas/mathml3.xsd
+```