Allow adding arbitrary arguments to the pandoc invocation (for basic citation support)

Relates to #21 - this is a quick intermediate fix to support citations, at the cost of being slightly less user friendly (docs can help though).

The idea is there should be a setting where you can add stuff like this to the command (from SkepticMystic):

--citeproc --csl "https://raw.githubusercontent.com/citation-style-language/styles/master/apa.csl" 
--bibliography "Zotero Exports\My Library.json" 
--reference-doc="Pandoc\Templates\APA7.docx" 

[OliverBalfour]

FYI @tim-hilde @mafsi I’ve added some documentation about getting citations working here (I actually tested it this time!): https://github.com/OliverBalfour/obsidian-pandoc/wiki/Citations-(work-in-progress) It’s a little fiddly at this stage but it works for now

[mafsi]

Yes, it is. The issue is that the citation syntax works if you use a markdown input to Pandoc, but my plugin uses an HTML input. I’ve added an option to use a markdown input which should make citations work but will break non-standard markdown syntax from eg DataView

Yeah, the problem with Obsidian Plugins is that they are far from standard. I like to keep as close to standard as possible for the time when I will switch from Obsidian to other editor.