Automatically set category incoming email address based on slug

[LeoMcA (Leo McArdle)]

ついにメール受信設定の移行準備が整いつつあるため、このプラグインを作成しました：

Automatically set category email-in addresses

This plugin takes 4 settings: auto_email_in_enabled auto_email_in_divider: Set the divider between a parent category slug and sub category slug auto_email_in_domain: Set the domain of the email-in addresses auto_email_in_append: Append new email-in addresses, rather than overwriting So with the default settings, when enabled, all category email-in addresses will be set to: <slug>@example.com or <parent_slug>+<child_slug>@example.com So, with a category under /c/help/faq, this would be hel…