Normalization of horizontal rulers

[jolars]

At the moment, we normalize horizontal rulers to ---:

So, this:

*  *  *  *

---------------

becomes

---

---

The Pandoc rewrites this as

------------------------------------------------------------------------

------------------------------------------------------------------------

This poll proposes two options:

Pandoc-Style

Normalize to

-------------------------------------------------------------------------

but make the length match line-width

Pros

• Easier to dinstiguish from yaml metadata blocks and might even help in some edge cases to maintain idempotency
• Closer to the markdown philosophy of having the plain text be readable (maintain semantic meaning) as it is.

Current behavior

Normalize to --- everywhere.

Pros

• Probably more common?
• More minimalist

[jolars]

I went with the pandoc-style behavior.