[Tolk] Missing description for `createMessage()` and `.send()` functions and allowed modes

[cucumber-sp]

There's no documentation for createMessage({...}).send(mode) function neither possible mode values. Since mode naming is pretty different from Tact and other languages, it's def need to be there.

Modes example: SEND_MODE_CARRY_ALL_BALANCE | SEND_MODE_DESTROY | SEND_MODE_IGNORE_ERRORS