Add Minecraft address verification step

[bullishlucas]

Description

Adds the same public-address verification step to the English and German Minecraft domain guides. The new section explains how an independent Minecraft protocol check can separate DNS propagation from an unreachable port or invalid server response.

I maintain ServerBuddy, which this change links. This is a disclosed documentation contribution with no affiliate relationship or link exchange. I am not requesting and decline the €10 hosting credit offered for accepted contributions.

Type of Change

• New guide
• Updated guide
• Bug fix
• Sidebar / Navigation
• Other

Checklist

General

• The change exists in DE and EN.
• No sidebar entry is needed because both pages already exist.
• Existing frontmatter remains unchanged.

Formatting and content

• Existing heading and admonition conventions are preserved.
• Both translations cover the same verification step.
• The destination returns HTTP 200.

Verification

• npm run docs:build
• git diff --check