Added some useful African capitals

Added some useful African capitals

Not cities, but capital versions of some letters we already had in
lower-case for IPA.  Specifically:

U+0186 LATIN CAPITAL LETTER OPEN O
U+0189 LATIN CAPITAL LETTER AFRICAN D
U+0190 LATIN CAPITAL LETTER OPEN E
U+0196 LATIN CAPITAL LETTER IOTA
U+01B2 LATIN CAPITAL LETTER V WITH HOOK

Between them, Hyperglot thinks this gains us useful coverage of
languages with a few tens of millions of speakers, which seems like good
value to me.

The all also have small caps, and in the case of the African D all the
capital-D variants.