hreflang tags are missing

[jonoalderson]

Patterns URLs like https://fr.wordpress.org/patterns/ omit hreflang tags. These should be added, as per other parts of the wp.org site(s).

[dd32]

I believe these were disabled before the localised pattern directory was implemented, and before localised patterns were possible.

The code will also need updating to detect the localised variants of the patterns and only link to those (where the post name also differs)