lsp-mode client configuration for rescript-vscode LSP server for the ReScript Language.

For documentation see https://github.com/jjlee/rescript-mode

The server provides type information, compiler errors, completion, and code formatting (currently there's an lsp-mode bug that prevents formatting working).

This is experimental and Emacs is NOT SUPPORTED by the ReScript core team and the --stdio flag that this depends on, or the LSP server itself, may go away in a future release of rescript-vscode.