Add container with two columns

public/typo3conf/ext/ep_theme/Configuration/TCA/Overrides/tt_content_element_container.php

@@ -1,6 +1,19 @@
 <?php
 
 call_user_func(function () {
+    \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\B13\Container\Tca\Registry::class)->configureContainer(
+        new \B13\Container\Tca\ContainerConfiguration(
+            'ep_container_halves',
+            'Zweispalter',
+            '50/50 Aufteilung',
+            [
+                [
+                    ['name' => 'Elemente', 'colPos' => 300],
+                ]
+            ]
+        )
+    );
+
     \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\B13\Container\Tca\Registry::class)->configureContainer(
         new \B13\Container\Tca\ContainerConfiguration(
             'ep_container_thirds',
@@ -43,7 +56,7 @@ call_user_func(function () {
         '
     ];
 
-    foreach (['ep_container_thirds', 'ep_container_teasergroup'] as $field) {
+    foreach (['ep_container_halves', 'ep_container_thirds', 'ep_container_teasergroup'] as $field) {
         $GLOBALS['TCA']['tt_content']['types'][$field] = array_replace_recursive(
             $GLOBALS['TCA']['tt_content']['types'][$field],
             $headerConfig

public/typo3conf/ext/ep_theme/Configuration/TypoScript/ContentElements/container.typoscript

@@ -1,3 +1,14 @@
+tt_content.ep_container_halves =< lib.contentElement
+tt_content.ep_container_halves {
+    templateName = Halves
+    templateRootPaths {
+        10 = EXT:ep_theme/Resources/Private/Templates/Container
+    }
+    dataProcessing {
+        100 = B13\Container\DataProcessing\ContainerProcessor
+    }
+}
+
 tt_content.ep_container_thirds =< lib.contentElement
 tt_content.ep_container_thirds {
     templateName = Thirds