Remove Media Guide

The canonical logo policy and media guide is now hosted on the Rust Foundation website

https://foundation.rust-lang.org/policies/logo-policy-and-media-guide/

Author: JoelMarcey

locales/en-US/media-guide.ftl

@@ -7,7 +7,6 @@ policies-page-description = This page links to the comprehensive set of Rust’s
 
 policies-code-of-conduct-link = Code of Conduct
 policies-licenses-link = Licenses
-policies-media-guide-link = Logo Policy and Media Guide
 policies-security-link = Security Disclosures
 policies-privacy-link = Privacy Notice