Write tutorial on using this plugin

[arkgil]

This should include:

• downloading and compiling
• starting erlangpl with Elixir support (currently only from feature branch)
• providing path to plugin as argument
• opening WS connection from the browser and installing on-message handler

[baransu]

I'm thinking how can we combine front and backend plugins into one plugin. For example if someone is creating additional functionality, we dont want that someone to create two repositories for frontend and backend part of plugin.

And there should be option to create only "half" of plugin as well. We should think about it.

I'm currently almost able to run UI in development mode, on erlangpl-ui standalone dev server.

[arkgil]

I'd love to wrie frontend plugin for this backend, but I think the process is too complicated to show it as an example Elixir plugin. But when we are ready with plugin system, I'm on it!

[michalslaski]

In the old UI all plugins were required to return HTML menu element from the init function, but it is no longer the case in the new UI.

[arkgil]

Thanks @michalslaski, fixed that in 74d5b0a

[arkgil]

I've added the walkthrough, as always, feedback is welcome 😉