I was very glad with the release of Custom Metadata Type Settings. But there are limited number of field types that we can create (similar to custom settings). It would be hugely useful if “Rich Text” and “Lookup” field types can be added.
Here are the 2 ideas that needs your votes!
Need ‘Rich Text’ field type in Custom Metadata Type
https://success.salesforce.com/ideaView?id=08730000000LiQ4AAK
Need ‘Lookup’ field in Custom Metadata Types
https://success.salesforce.com/ideaView?id=08730000000LiQ9AAK
Keep voting!
sfdcFanBoy 
The team is actively working on delivering a relationship field type on custom metadata types.
Farther out on our roadmap, we definitely hope to deliver Long Text fields. We’re evaluating Rich Text fields as a possible target as well.
LikeLiked by 1 person
Thank you, good to hear that!
LikeLike