Adds extensive legacy URL redirects to docs (#510)

Introduces a plugin for client-side redirects and configures
redirects from numerous old documentation URLs to their new
locations, improving navigation for users with outdated links.

Also normalizes a sidebar label and updates a page title for
clarity and consistency.

Signed-off-by: Sivanantham Chinnaiyan <sivanantham.chinnaiyan@ideas2it.com>

Author: sivanantha321

docs/model-serving/predictive-inference/explainers/overview.md

@@ -1,5 +1,5 @@
 ---
-title: InferenceService Explainer
+title: Overview
 description: An overview of model explainability in KServe
 ---