Fixes author & core filename casing

[neil-morrison44]

• if you'd prefer to keep the capitalised JOTEGO in the UI the folder names will need changed (with them being removed / re-added to git so it picks up on it)
• https://www.analogue.co/developer/docs/directories-and-sd-folder-structure#cores
• Casing doesn't matter much on windows / the pocket itself but it can throw up issues elsewhere

(this is from running the validator as part of the multi-zip workflow PR which's coming soonish)