While you can develop ElixirLS on its own, it's easiest to test out changes if you clone the [vscode-elixir-ls](https://github.com/elixir-lsp/vscode-elixir-ls) repository instead. It includes ElixirLS as a Git submodule, so you can make your changes in the submodule directory and launch the extension from the parent directory via the included "Launch Extension local" configuration in `launch.json`. See the README.md on that repo for more details.
