use TYPO3\CMS\Core\Information\Typo3Version;
use TYPO3\CMS\Core\Utility\ExtensionManagementUtility;
use TYPO3\CMS\Core\Utility\GeneralUtility;

$versionInformation = GeneralUtility::makeInstance(Typo3Version::class);
// Only include page.tsconfig if TYPO3 version is below 12 so that it is not imported twice.
if ($versionInformation->getMajorVersion() < 12) {
   ExtensionManagementUtility::addPageTSConfig('
      @import "EXT:wseils/Configuration/TsConfig/Page/Mod/WebLayout/BackendLayouts.tsconfig"
   ');
}

// RTE
if (!(bool) $bootstrapPackageConfiguration['disablePageTsRTE']) {
    \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig('<INCLUDE_TYPOSCRIPT: source="FILE:EXT:wseils/Configuration/TsConfig/Page/RTE.tsconfig">');
}


// Add RTE configuration
$GLOBALS['TYPO3_CONF_VARS']['RTE']['Presets']['rteTheo'] = 'EXT:wseils/Configuration/RTE/MyConfiguration.yaml';