docs: write the Play Store listing in every language

[blckntr]

A fuller store listing for every app language, in store/listing/<lang>/: title, short description and full description, to paste into the Play Console. The texts follow the app as it is, with its real figures, and fit the Play Store limits (title 30, short description 80, full description 4,000 characters).

• English and French. The description lists the 8 countries and their 21 operators and the mobile money services by name (the words people search for), then covers parameter codes, direct run with the operator's reply, the bundle comparator (for now Benin, Togo and Orange Côte d'Ivoire, the operators with plans in the catalog), favorites, personal codes, the Quick Settings tile, device codes and catalog updates.
• It ends with a line saying the app is independent from the operators, which Google expects when operator names appear in a listing.
• The titles add "Africa" / "Afrique" to the name. This is only a proposal.