How to add newelements?

[webmarts2019]

Hi
Is there any way we can add additional elements like line, arrow etc.
Also is there any way to set the properties like border, size , color of the element

[breakfasting]

FYI my development on this project is currently paused, please feel free to contribute though!

svgelements like lines and arrows are currently hardcoded into the frontend, however the infrastructure could easily support adaptations of these elements coming from the backend, and having an UI and corresponding endpoints manage them

no support for element borders currently, but size and color should be supported!