Security page: "Responsible Disclosure" is a second H1 placed after the closing info box #450

The Security page renders two <h1> headings: the page title "Security", and the "Responsible Disclosure" section further down.

# Responsible Disclosure

Source: https://github.com/WordPress/hosting-handbook/blob/main/security.md?plain=1#L166

Every other section on the page uses ## or deeper, and no other handbook page has a second H1. On the live page this produces:

<h1 id="responsible-disclosure" class="is-toc-heading" ...>Responsible Disclosure</h1>

The page then has two top-level headings, which breaks the heading outline for screen reader users. The section also sits after the closing [info] box ("If you're interested in improving this handbook..."), which every page ends with, so it reads like an afterthought below the page footer note.

Fix: change it to ## Responsible Disclosure and move the section above the closing [info] box, for example right after "WordPress Automatic Updates".

AI Assisted Claude Code ran markdownlint over the repo and flagged the second H1. The rendered <h1> was then confirmed on the live page.