make simple test landing pages

- add HomeController
- add index.html
- add layout.html
- add management.js
- add management.css
- add css js and html to .editorconfig

src/main/kotlin/ltd/hlaeja/controller/HomeController.kt

@@ -0,0 +1,13 @@
+package ltd.hlaeja.controller
+
+import org.springframework.stereotype.Controller
+import org.springframework.ui.Model
+import org.springframework.web.bind.annotation.GetMapping
+
+@Controller
+class HomeController {
+
+    @Suppress("UnusedParameter", "FunctionOnlyReturningConstant")
+    @GetMapping("/")
+    fun home(model: Model): String = "home/index"
+}