Role archives and history page

From @astrofrog:

> Somewhere (doesn't have to be too obvious necessarily) we should keep a list of people who were previously in roles, so that there is an official place we record this (because I think we should recognize past as well as current contributions)

未指定任何檔案、測試或進入點。檢查現有的角色頁面和網站導覽，以確定歷史清單應放置在哪裡，然後與 maintainer 確認預期的人員、角色和呈現方式；當過去的角色持有人擁有一個官方且容易找到的歷史頁面時，即表示完成。

由索引模型根據 Issue 內容生成。