Zotero plugin support

[muety]

Not sure if this is the right place to throw in ideas for new plugins, but I'd love to have a Zotero one!

Some useful links:

• List of Zotero plugins
• Hello World plugin

OS, editor and machine are straightforward. The currently opened document's title could map to the entity property. Type could be something like "reading". Branch and language would remain empty. For the project, we could think of having a certain syntax for labels, e.g. if you add wakatime:Master Thesis to a document, it would be counted for that project. Or, alternatively, project corresponds to whatever folder a document is placed into.

[charveey]

I like this idea

[alanhamlett]

Duplicate of #942