use template placeholders instead of html

Signed-off-by: Joas Schilling <coding@schilljs.com>

core/Command/Db/Migrations/GenerateCommand.php

@@ -38,7 +38,7 @@ class GenerateCommand extends Command {
 
 	protected static $_templateSimple =
 		'<?php
-namespace <namespace>;
+namespace {{<namespace}};
 
 use Doctrine\DBAL\Schema\Schema;
 use OCP\Migration\SimpleMigrationStep;
@@ -47,7 +47,7 @@ use OCP\Migration\IOutput;
 /**
  * Auto-generated migration step: Please modify to your needs!
  */
-class <classname> extends SimpleMigrationStep {
+class {{classname}} extends SimpleMigrationStep {
 
 	/**
 	 * @param IOutput $output
@@ -66,7 +66,7 @@ class <classname> extends SimpleMigrationStep {
 	 * @since 13.0.0
 	 */
 	public function changeSchema(IOutput $output, \Closure $schemaClosure, array $options) {
-<schemabody>
+{{schemabody}}
 	}
 
 	/**
@@ -133,9 +133,9 @@ class <classname> extends SimpleMigrationStep {
 
 
 		$placeHolders = [
-			'<namespace>',
-			'<classname>',
-			'<schemabody>',
+			'{{namespace}}',
+			'{{classname}}',
+			'{{schemabody}}',
 		];
 		$replacements = [
 			$ms->getMigrationsNamespace(),