feat: add Elixir module (#437)

src/configs/starship_root.rs

@@ -31,6 +31,7 @@ impl<'a> RootModuleConfig<'a> for StarshipRootConfig<'a> {
                 // ↓ Toolchain version modules ↓
                 // (Let's keep these sorted alphabetically)
                 "dotnet",
+                "elixir",
                 "elm",
                 "golang",
                 "haskell",