Fix kamalen ngɔni description, check invention relationship (and add relationships as improvement)

kamalen ngɔni

1. Description is almost an extract of Wikpedia and not completely true (twofold issue):
   In particular, kamalen ngɔni is not necessarily smaller and higher-tuned, it often comes with additional strings instead.
   Alternative: modern variant of donso ngɔni intended for young people, it comes with more strings and/or smaller size and higher pitch
2. Uncertain relationship: I did not find precise information on the fact that it has been invented by Alata Brulaye in 1960, but it seems to have been created in the '40s/'50s according to Hery's comment based on Eric Charry's book.
3. Missing relationships: the same than for donso ngɔni.

• (Checked aliases and ngɔni relationship which seem to be all fine )