RSS-based insights

Some kinds of remote information is useful to mail admins, like news about botnets, spam surges, etc. To allow receipt of such items, add support for RSS-feed-based insights. The RSS feed should probably be cached locally to avoid unnecessary polling, and page load should not be delayed by waiting for fetching.

Requirements

• Control Center should periodically fetch a feed source in the https://lightmeter.io website into a document (in memory).
• For each result in such document, in case there's already an insight for it, it's skip. Otherwise a new insight in the category News for it should be generated.
• Such insight should have a title and a description obtained from the feed result. They should be short texts. A button "show more" should be displayed, linking the original page where the user can obtain more information about the news that the insight refers to.
• Errors reading from such feeds should be logged to the terminal.

Example of URL (TODO: define the right URL): https://lightmeter.io/category/releases/?feed=rss2

Open questions:

• How to handle translation of such insights?