added curry language definition for syntax highlighting

I'm working with [Curry](https://curry-lang.org/) recently. For syntax highlighting in ecode I added a `curry.json` file to `~/.config/ecode/languages/`. That works fine, but I will forget about this tweak soon. So I though I propose to add this language to ecode directly. Curry is very similar to Haskell, so I just copied it's definition and modified it slightly. Feel free to reject this PR, in case you consider Curry to niche, or if I did not do this correctly. *** I also have a related question: Comments for Haskell or Elm are defined as `%-%-`. But that is not correct, should just be `--`. I set my .json file for these languages now to ```json { "comment": "--", "files": [ "%.hs$" ], "name": "Haskell", "patterns": [ { "pattern": [ "%-%-", "\n" ], "type": "comment" }, ... ``` That works fine for me. Should this also be the default setting?