[lsp4e-dev] Is there a simple example for implement basic editor feature

[Christoph Läubrich <laeubi@xxxxxxxxxxxxxx>]

The introduction [1] mentioned

> The first thing you should do is to implement your language server.
> To do so just implement the interface

I have tried so and its nut very intuitive to "just" implement that 
interface, so I wonder if there is an example somwhere that shows setup 
for a basic language including:

- auto completion
- code folding
- syntax highlighting
- error markers
- ...

That would be really helpful for people trying to adapt for the language 
server concept.

[1] https://github.com/eclipse/lsp4j/blob/master/documentation/README.md