Option to specify the plantuml delimiter

[andre-stoesel]

I created this pull request to solve the problem from issue #92.

The export of gitlab flavored markdown file with plantuml drawings work fine, if the opening delimiter is set to ```plantuml and the closing delimiter is set to ```.

[ChrisTuckerNM]

Approved yet? Implemented?

[paussems]

Would be nice if this patch gets merged

[bvella]

I am using this patch to be able to convert markdown files to pdf that use gitlab style diagrams, i.e. code block with plantuml language. Can this be merged or some feedback provided? I hate to have to ask developers to manually patch the plugin to be able to export a pdf

[PetrGasparik]

Please merge this patch.

BTW I tried to apply it by changing c:\Users<user>.vscode\extensions\yzane.markdown-pdf-1.2.0 foles and it didn!t help. I understand that I need markdown-it-plantuml plugin but how to get it? VSCode for windows

[anorm]

I would also love to see this patch merged. Using vscode with "PlantUML" jebbs.plantuml and "Markdown PDF" yzane.markdown-pdf extensions makes for a perfect combo.

[patmuk]

Please release 1.2.1 as soon as possible, this is a highly desired feature!

[yzane]

Thanks for your PR!