Version 0.41.0

Added the developer's GitHub account, and the public part of the NMTS source, to the developer's letter.

The letter already carried the X account and the Discord server; the GitHub account was nowhere on the screen, and the public repository was reachable only from sign-up, sign-in, the account screen and the footer. The letter is where someone reads about who is building this, so both now sit at its foot: the account, and beside it the cryptography engine that is open source. What is public is the engine, not the server or the screens, and the label says so.

Fixed the copy button sitting at the far edge of the letter instead of beside the donation address.

The address took whatever width was left over, so on a wide screen the text ended and an empty stretch ran on to the button. The address and the button are now one run of text: the button follows the last character, and when the address wraps the button goes with it.