Improve what help the autocompletion offers

[xmacex]

The company autocompletion framework used by scel can offer more help in the completion popup miniwindows. Currently it completes top level objects, which works very well

Compare with Elpy for Python, which also uses the eldoc to display arguments in the echo area at the bottom of the screen

Mads has something like this in what looks like vi on his quarantine livecoding stream

The autocompletion could show a oneline description e.g.

SynthDef - Client-side representation of a synth definition

and method completion on dot (e.g. from the SuperCollider IDE)

completion of symbols (from Mads' quarantine livecoding stream)

Company is quite powerful, and together combined with eldoc I believe a pretty well guided interaction with SuperCollider can be achieved for Emacs :)

[xmacex]

Ok I just discovered the existence of sclang-extensions which improves autocomplete for sclang-mode and does Eldoc thing too. It is unmaintained, but I'm sure worth excavating.

[TatriX]

Does it work, have you tried?

[xmacex]

It didn't work for me, instead giving errors when auto-complete runs. I'm not sure if it would be worth trying to bring the sclang-extensions package back to action from it's unmaintained status, or try to re-implement the functionality with company in the scel package itself.

[rrrnld]

I have added eldoc support in #61, it was actually just a single line of code. I saw better eldoc support in other modes, but given how small the change is I think this is already quite the improvement.