Update template-syntax.md
Update template-syntax.md

Blocks usage example added
quantum13/yii2-twig,yiijan/yii2-twig,yiisoft/yii2-twig,andrew-kamenchuk/yii2-twig,pana1990/yii2-twig,pana1990/yii2-twig,andrew-kamenchuk/yii2-twig,yiijan/yii2-twig,quantum13/yii2-twig