Add support for ruby-lsp

**Name:** ruby-lsp
**URL:** https://github.com/Shopify/ruby-lsp

ruby-lsp is a new LSP implementation from Shopify. It is now the [recommended Ruby LSP implementation for VS Code](https://code.visualstudio.com/docs/languages/ruby#_install-the-ruby-lsp-extension-in-vs-code).

I had a quick stab at implementing support for this myself in ALE, but discovered that [ruby-lsp only supports incremental text synchronization](https://github.com/Shopify/ruby-lsp/issues/575#issuecomment-1485839623) for `textDocument/didChange` notifications, so this might be blocked on #4456. I thought I'd capture what I'd discovered here anyway.

Thank you for ALE! 🙌