I've made some changes to comments so you can now reply to and like them.
You can also now comment on a language or hackroom, which is new and more complicated than it sounds.
Comments have a 'commentable', which is polymorphic and can be anything you like. In this case we add the relation to the language model as
has_many :comments, as: :commentable, polymorphic: true
This tells Rails all comments with this language add...