Use solargraph for code autocomplete

[numbcoder]

The rcodetools’ development is not active, solargraph looks better

https://github.com/castwide/solargraph

[doudou]

Given that solargraph focusses on code completion, and develops its own VSCode extension, I would suggest to remove completion support completely from vscode-ruby, and simply depend on the solargraph extension. Even better, approach the solargraph developer(s) to get all the gems and extensions under the same org (rubyide would sound like a good choice).

[castwide]

Adding a dependency is definitely the easiest way to integrate Solargraph. I created a fork and a pull request for it.

[wingrunr21]

Closing for issue cleanup. Apologies if this is still an issue. We are working to improve the core extension experience.