We anticipated three content types: “Conversations” (a generalized interview), “Images” (appropriate for show catalogues or portfolios), and “Text” (catchall text-based content). There’s also “Other” on by default.
If you seek to shrink or expand this list, start in _config.yml and simply edit the variable content-types. If you want a multi-word content type, please wrap it in quotes in _config.yml, but don’t wrap it in quotes in your post files.
Reminder: you must rebuild if you make a change to _config.yml to see the changes appear.
And as a final point: layouts and content-types do not need to be one and the same!