More methods to use parsedown features from outside

[trendschau]

Thank you very much for parsedown, I use it for my flatfile cms typemill and parsedown is one of the most important parts!

One idea: Markdown has a lot of cool features, but these features are hardly accessible from outside of parsedown. For example:

• I often use the content array from $this->linesElements before it is turned into markup. In this case it is quite easy to overwrite and split the function.
• I also need a reliable detection of block-level elements because I need to split the markdown content into an array of markdown-blocks for my block-editor. Parsedown has this block-detection, but it is a bit hard to overwrite the whole method linesElements() for this.

Not sure if this is a common requirement but for me it would be awesome if parsedown provides some methods to use the incredible features from outside without the need to customize and overwrite core-methods of parsedown...