Allow external use for publishing

[matfire]

I really like the workflow of using magiedit for writing articles for my blog, but some people may have other tools they use for writing (typora, obsidian or any other I haven't heard about).

This issue tracks allowing external tools to talk to magiedit to publish articles, set up other publishing destinations and such.

For this to work magiedit needs to:

• allow api key management
• expose a set of endpoints to
• • handle publishers (CRUD)
• • publish articles
• • add an article to magiedit
• • get an article for magiedit

Of all these endpoints, the most time-consuming one I estimate will be allowing the creation of publishers, but the others should follow easily enough.