Don't do this:
Notice how "example", "image", "player" folder names simply contain many related packages, yet they use singular form.
Because it's consistent with the style the Go project uses.
There are packages in the standard library in conflict with this: bytes, errors and strings.
@vladimiroff I don't think those are counter-examples. Neither bytes, errors, nor strings are collections. They're individual packages.
By collection, I mean something like...
It contains encoding/json, encoding/xml, encoding/gob, etc. Notice how it's encoding/json and not encodings/json. It's because the collection folder encoding uses singular form.
Also, this suggestion is primarily for empty folder names that simply contain many packages.