>in fact the manual only really covers login and getting prices
Mmm. Not sure you've got to the end of the manual yet, since all the basic operations you need are documented (login, finding and getting markets, getting market prices, placing bets, updating, canceliing bets), along with detailed examples of use (in fact there is more explanation than you usually have in an R package).
But it's true that we haven't documented all individual functions at the package level. You should find most that don't have examples in the manual are fairly obvious once you've started using the package, alongside basic R functions like args("functionname"). We may add more doc when there is time, but for now there's the manual - and don't forget users can contribute, also, since this is open source code.