Merge pull request mnapoli#23 from benharri-forks/php8

support php 8.0

Merge pull request mnapoli#21 from tomcoonen/symfony5

Added Symfony 5 compatibility. Dependency updates.

Merge pull request mnapoli#16 from petk/symfony4

Add Symfony 4 support

Merge pull request mnapoli#13 from kelunik/fix-preg-quote

Fix preg_quote to escape delimiter as well

Merge pull request mnapoli#11 from petemcfarlane/master

Update dependency symfony/yaml to use "~2.1|^3.0"

Added a bridge to the league/commonmark Markdown parser

PSR-2 fixes

Merge pull request mnapoli#6 from Giuseppe-Mazzapica/alt-separators

Flexible configuration for YAML Front Matter separators. Fixes #5

Merge pull request mnapoli#4 from Giuseppe-Mazzapica/issue-3

Use regex-based approach to extract front matter

Dependency injection for ParsedownParser