Provide steps to download configuration from Horizon panel (#76)

Co-authored-by: sausin <sausin@users.noreply.github.com>

README.md

@@ -84,8 +84,9 @@ and you should now have a working OVH Object Storage setup :smile:.
 
 The environment variable `OS_AUTH_URL` is normally not going to be any different for OVH users and hence doesn't need to
 be specified. To get the values for remaining variables (like `OS_USERNAME`, `OS_REGION_NAME`, `OS_CONTAINER_NAME`,
-etc... `OS_PROJECT_ID` is equivalent to `OS_TENANT_ID`), you can download the configuration file with details in your OVH control panel
-(`Public cloud -> Project Management -> Users & Roles -> Download Openstack's RC file`). 
+etc... `OS_PROJECT_ID` is equivalent to `OS_TENANT_ID`), you can download the configuration file with details from OVH's Horizon or Control Panel:
+- **OVH Control Panel**: `Public cloud -> Project Management -> Users & Roles -> Download Openstack's RC file`
+- **OVH Horizon**: `Project -> API Access -> Download OpenStack RC File -> Identity API v3`
 
 Be sure to clear your app's config cache after finishing this library's configuration:
 ```sh