docs,test: fix kubeconfig typo and clarify env var overrides (#558)

* docs: fix typo and clarify kubeconfig deserialization issue

- Corrected 'applicaiton/yaml' to 'application/yaml'
- Reworded paragraph for clarity and consistency
- Updated variable name from 'clust_id' to 'cluster_id' to match usage elsewhere in README

* test: add inline comments for env var overrides in defaults.py

- Documented each overrideable default using consistent, concise comments
- Improved onboarding clarity for contributors customizing integration tests

---------

Co-authored-by: DO-rrao <[email protected]>

Author: rajghosh06-dev

README.md

@@ -217,7 +217,7 @@ docker run -it --rm --name pydo -v $PWD/tests:/tests pydo:dev pytest tests/mocke
 
 #### `kubernetes.get_kubeconfig` Does not serialize response content
 
-In the generated python client, when calling client.kubernetes.get_kubeconfig(clust_id), the deserialization logic raises an error when the response content-type is applicaiton/yaml. We need to determine if the spec/schema can be configured such that the generator results in functions that properly handle the content. We will likely need to report the issue upstream to request support for the content-type.
+In the generated Python client, calling client.kubernetes.get_kubeconfig(cluster_id) raises a deserialization error when the response content-type is application/yaml. This occurs because the generator does not correctly handle YAML responses. We should investigate whether the OpenAPI spec or generator configuration can be adjusted to support this content-type. If not, the issue should be reported upstream to improve YAML support in client generation.
 
 Workaround (with std lib httplib):
 

tests/integration/defaults.py

@@ -5,15 +5,23 @@
 
 from os import environ
 
+# Prefix used for naming test resources
 PREFIX = "cgtest"
 
-# CUSTOMIZABLE
+# Default droplet size slug. Override with DO_DROPLET_SIZE.
 DROPLET_SIZE = environ.get("DO_DROPLET_SIZE") or "s-1vcpu-1gb"
+
+# Default droplet image slug. Override with DO_DROPLET_IMAGE.
 DROPLET_IMAGE = environ.get("DO_DROPLET_IMAGE") or "ubuntu-22-04-x64"
 
+# Default Kubernetes version. Override with DO_K8S_VERSION.
 K8S_VERSION = environ.get("DO_K8S_VERSION") or "latest"
+
+# Default size slug for Kubernetes nodes. Override with DO_K8S_NODE_SIZE.
 K8S_NODE_SIZE = environ.get("DO_K8S_NODE_SIZE") or "s-1vcpu-2gb"
 
+# Default region for resource creation. Override with DO_REGION.
 REGION = environ.get("DO_REGION") or "nyc3"
 
+# UUID used for invoice PDF tests. Override with DO_INVOICE_UUID.
 INVOICE_UUID_PARM = environ.get("DO_INVOICE_UUID") or "something"