docs: Add Lua formatters section (stylua) (#24101)

docs/src/languages/lua.md

@@ -28,3 +28,44 @@ See [LuaLS Settings Documentation](https://luals.github.io/wiki/settings/) for a
   ]
 }
 ```
+
+## Formatting
+
+Zed can enable auto-formatting of code with formatters like [StyLua](https://github.com/JohnnyMorganz/StyLua).
+
+1. Install [StyLua](https://github.com/JohnnyMorganz/StyLua): `brew install stylua` or `cargo install stylua --features lua52,lua53,lua54,luau,luajit` (feel free to remove any Lua versions you don't need).
+2. Add the following to your `settings.json`:
+
+```json
+{
+  "languages": {
+    "Lua": {
+      "format_on_save": "on",
+      "formatter": {
+        "external": {
+          "command": "stylua",
+          "arguments": ["--syntax=Lua54", "-"]
+        }
+      }
+    }
+  }
+}
+```
+
+You can specify various options to StyLua either on the command line above (like `--syntax=Lua54`) or in a `stylua.toml` in your workspace:
+
+```toml
+syntax = "Lua54"
+column_width = 100
+line_endings = "Unix"
+indent_type = "Spaces"
+indent_width = 4
+quote_style = "AutoPreferDouble"
+call_parentheses = "Always"
+collapse_simple_statement = "All"
+
+[sort_requires]
+enabled = true
+```
+
+For a complete list of available options, see: [StyLua Options](https://github.com/JohnnyMorganz/StyLua?tab=readme-ov-file#options).