Add lexical for linting elixir projects (#4580)

supported-tools.md

@@ -177,6 +177,7 @@ formatting.
   * [dialyxir](https://github.com/jeremyjh/dialyxir)
   * [dogma](https://github.com/lpil/dogma) :floppy_disk:
   * [elixir-ls](https://github.com/elixir-lsp/elixir-ls) :warning:
+  * [lexical](https://github.com/lexical-lsp/lexical) :warning:
   * [mix](https://hexdocs.pm/mix/Mix.html) :warning: :floppy_disk:
 * Elm
   * [elm-format](https://github.com/avh4/elm-format)