add flush to compatibility list
page: 'filter'
- name: 'flush'
twigLink: 'https://twig.symfony.com/doc/2.x/tags/flush.html'
- support: 'none'
+ support: 'full'
+ page: 'flush'
- name: 'for'
twigLink: 'https://twig.symfony.com/doc/2.x/tags/for.html'
support: 'full'
