Formats frontmatter into one line

[franchb]

Original markdown with front matter

---
id: how-to-use
title: How to Use
order: 3
description: Professional vulnerability analysis methodologies using the catalog
---

# Title

text

Output:

mdfmt matter.md 
## id: how-to-usetitle: How to Useorder: 3description: Professional vulnerability analysis methodologies using the catalog

# Title

text

Expected:

---
id: how-to-use
title: How to Use
order: 3
description: Professional vulnerability analysis methodologies using the catalog
---

# Title

text

[atlet99]

Hey, @franchb
Thanks for finding the error, I really missed those points when I was thinking about the idea. So, I'll try to fix it ASAP. If you want to help with something, I open for any PR with your ideas.

Best regards,
Abdurakhman Rakhmankulov.