Add docker files to gitignore (#6507)
Add docker files to gitignore (#6507)

* add docker files to gitignore

* Update .gitignore

airbnb/caravel,airbnb/caravel,zhouyao1994/incubator-superset,apache/incubator-superset,airbnb/superset,apache/incubator-superset,zhouyao1994/incubator-superset,zhouyao1994/incubator-superset,zhouyao1994/incubator-superset,apache/incubator-superset,airbnb/superset,mistercrunch/panoramix,mistercrunch/panoramix,airbnb/caravel,mistercrunch/panoramix,apache/incubator-superset,mistercrunch/panoramix,airbnb/superset,airbnb/caravel,zhouyao1994/incubator-superset,airbnb/superset,apache/incubator-superset