docs: Add a paragraph to link to later.js for schedules (#4706)
docs: Add a paragraph to link to later.js for schedules (#4706)

I find it unclear what exactly is supported by Renovate in terms of parsing text for schedules. By looking at the code, I can see that it seems to use later.js which has good documentation. I've added a link to their documentation for people who want to know more.
singapore/renovate,singapore/renovate,singapore/renovate