Add customizable liveness and readiness probes

[mattmattox]

This PR introduces the ability to customize the liveness and readiness probes through the chart's values.yaml. Users can now adjust the initial delay, period, timeout, success threshold, and failure threshold for both probes. Additionally, it's now possible to disable either probe by setting the enabled flag to false.

This enhancement improves the flexibility of the deployment configurations, allowing users to tailor the health check mechanisms to better suit their specific service requirements and operational environments.

Changes made:

• Updated values.yaml to include default configurations for liveness and readiness probes. (Doesn't change the default behavior)
• Modified deployment.yaml to use the values from values.yaml for setting up the probes, including conditional checks to enable or disable them as configured.

This change resolves #96, addressing the need for more configurable liveness and readiness probes as requested by the community.

[martin-helmich]

LGTM; thanks for your contribution. 🙂👍 Give me a ping (either here, or on the Kubernetes Slack) whenever you want me to tag a new release.