Setext-style headers are not recognized

[TimsManter]

Just look at First header:

Title
=====
<!-- TOC  -->

- [Second](#second)

<!-- /TOC -->

First
-----

### Second

Title
=====
<!-- TOC -->

- [First](#first)
    - [Second](#second)

<!-- /TOC -->

## First

### Second

After TOC update setext-style is not recognized but atx-style works as expected. This is very inconvenient for me as all my notes use setex-style.

• Extension version: 1.4.3
• VS Code version: 1.8.1

Really good extension by the way :).

[alanwalk]

Recognized title and ignore other grammar, it 's troublesome, I need a lot's time. Thank you for your issues.