update taint key naming instructions

Author: ketanjani21

docs/book/src/user-guide/getting-started.md

@@ -144,13 +144,24 @@ Use unique, descriptive taint keys for different readiness checks.
 
 #### Taint Key Naming
 
-Follow [Kubernetes naming conventions](https://kubernetes.io/docs/concepts/overview/working-with-objects/names/):
+Follow [Kubernetes naming conventions](https://kubernetes.io/docs/concepts/overview/working-with-objects/names/).
 
-*   Use DNS-style prefixes: `readiness.k8s.io/`, `example.com/`
-*   Be descriptive: `readiness.k8s.io/cni-ready` vs. `rdy`
-*   Use alphanumeric, `-`, `.`, `/`, `_`
+Taint keys must have the `readiness.k8s.io/` prefix to clearly identify readiness-related taints and avoid conflicts with other controllers
+
+**Valid:**
+```yaml
+taint:
+  key: "readiness.k8s.io/NetworkReady"
+  key: "readiness.k8s.io/StorageReady"
+```
+
+**Invalid:**
+```yaml
+taint:
+  key: "network-ready"              # Missing prefix
+  key: "node.kubernetes.io/ready"   # Wrong prefix
+```
 
-<!-- TODO: Update this section once PR #112 is merged to document the readiness.k8s.io/ prefix restriction -->
 
 ## Configuration