Consider adding a reference to Cron format which does not require navigating away

[krassowski]

Problem

Users somewhat familiar with Cron wanted to use it but did not remember the syntax. Working in environments without internet access they could not open the link to https://www.gnu.org/software/mcron/manual/html_node/Crontab-file.html available in the UI.

Proposed solution

Add a small reference example:

Current	Proposed
	*

• existing link can stay or be removed; please ignore non-matching "Interval" definition on figma snapshot.

Additional context

Proposed by @sketch0395