fix: move SECRET_KEY from Variables section

Move SECRET_KEY info to the next section on secrets

fixes issue #67

docs/deploy-apis-instance.md

@@ -59,11 +59,11 @@ Variables needed for deployment to work:
 * `PUBLIC_URL`: The endpoint your service should listen to
 * `SERVICE_ID`: This is the services issue ID in the internal redmine - you have to create that service issue beforehand
 * `K8S_SECRET_DJANGO_SETTINGS_MODULE`: This points to your Django settings. There is no default. See [the upstream documentation for details](https://docs.djangoproject.com/en/4.2/topics/settings/#envvar-DJANGO_SETTINGS_MODULE)
-* `K8S_SECRET_SECRET_KEY`: Deployment will be all right without this variable but user session problems similar to [issue 535](https://github.com/acdh-oeaw/apis-core-rdf/issues/535) might occur without this. Its value should be set to a strong string such as the output of `django.core.management.utils.get_random_secret_key`
 
 Any other variables you want to pass to your Django application have to be prefixed with `K8S_SECRET_` - this is a peculiarity of our deployment setup.
 
 Secrets you might want to add (important: after you save them in Github as secret, you wont be able to retreive it from there - so please store the secrets in your password manager):
 * `DATABASE_URL`: Your database URL - get it from the sysadmin team
+* `K8S_SECRET_SECRET_KEY`: Deployment will be all right without this but user session problems similar to [issue 535](https://github.com/acdh-oeaw/apis-core-rdf/issues/535) might occur without this. Its value should be set to a strong string such as the output of `django.core.management.utils.get_random_secret_key`
 
 Same as with the variables: other secrets you want to pass to Django have to be prefixed with `K8S_SECRET_`.