New keyboards for typing Nigerian languages

I’ve issued my first releases of keyboards for typing special Nigerian letters easily on a Mac.

These facilitate producing the following special letters: əɛɨɔa̱e̱u̱i̱o̱ɓɗƙ₦, and hígh tóne, lòw tòne, fâllîng tône, and nãsãl fõrms.