Add Cryptonote API

[davitb]

Add a simple REST API so that the link can be generated programmatically.

The caller would provide a text and the API would return a link.

[alainmeier]

👍 I'd love to make this at some point, it's definitely on the roadmap

[elimisteve]

+1

[immanuelfodor]

An API is really missing from this project, looks good on the frontend but should have curl support.