docs: remove dead Tokenization Architecture TOC entry (llm-d#1901)

The Tokenization Architecture section was removed when the UDS tokenizer
was replaced by the vLLM render sidecar, but its table-of-contents entry
was left behind. The #tokenization-architecture anchor no longer resolves
to any heading, so the link is dead. Drop the orphaned entry.

Signed-off-by: Anas Khan <83116240+anxkhn@users.noreply.github.com>

Author: anxkhn

DEVELOPMENT.md

@@ -32,7 +32,6 @@ Documentation for developing the llm-d Router.
     - [Filtered Tests](#filtered-tests)
     - [End-to-End Tests](#end-to-end-tests)
     - [Coverage](#coverage)
-  - [Tokenization Architecture](#tokenization-architecture)
   - [Kubernetes Development Environment](#kubernetes-development-environment)
     - [Infrastructure Setup](#infrastructure-setup)
     - [RBAC and Permissions](#rbac-and-permissions)