MD024: Allow hr separated sections to share titles/subtitles

[RonnyPfannschmidt]

when writing markdown presentations with markdown using hr as separator its sometimes helpful to repeat a larger title followup to #437

## topic
### part 1
---

## topic
### part 2
-----

## topic b
### part 1
---
## topic b
### part 2

i have that pattern in presentations that have short code snippets followed by output snipped

[DavidAnson]

This feels pretty specific - why not turn off MD024 for this scenario?

[RonnyPfannschmidt]

It's what i currently do,

I do prefer to minimise the linter ignores per project