[Localization] Normalize localization directory

[MalignantShadow]

~~I may or may not be working on a save editor~~ that includes localization/mod support for many mods (particularly, mods Replay provides crossover support for, as well as a few others). Part of this process includes extensive tooling and a custom mod that scans all supported mods for items and such, then extracting that info.

I noticed that Replay the Spire's localization doesn't explicitly put English translations into its own directory, when many other mods do (unless they only support English).

It'd be nice if those files were located in /localization/eng so I don't have to work around it :p. For now, I'll just write an if statement to cover this specific edge case, lol.