Fix #30, bug where the package cannot properly parse a file that contains Markdown code blocks with front matter in them

[caendesilva]

This PR fixes #30

The PR is fully backwards compatible as it does not change the existing parser, but instead adds a new one: YamlFrontMatter::markdownCompatibleParse() which uses code by https://github.com/eklausme (I hope this is okay, I'm happy to add you as a co-author if you see this!

Before:

After:

The source markdown used for the example: (with the inline backticks replaced)

---
title: test
foo: bar
---

A paragraph in a Markdown Post.
This file contains a Markdown code block that the original parser does not handle.
See https://github.com/spatie/yaml-front-matter/discussions/30.

'''
---
title: The Title of Markdown Code
---

A paragraph in Markdown Code
'''

[caendesilva]

Okay I refactored the code to use an improved version of what I used for the Hyde framework. I'm converting everything to arrays, which may be a bit inefficient but I think it makes it much more readable and understandable. I also added two more tests. Let me know if its okay or if I should change anything else.

This is my first community PR so I'd love to get feedback for the many more I hope to make :)

[caendesilva]

Let me know if there is anything else I can improve!

Also, @freekmurze, I really want to thank you for taking the time to give me such great feedback and helping me become a better developer! This is my first time contributing to a community package and thanks to you I feel like I have learned a lot!

[caendesilva]

Okay, pushing the commits now. I made it all in separate commits as I think that makes it easier to follow. I assume you will probably squash them before merging. As you can see I did not change the double quotes to single quotes as I wanted to await your input on the concern I placed as a comment in the first change conversation.

[freekmurze]

Thank you!

[caendesilva]

That's super cool! Thank you!