updated logo in readme and r# shorthand

rm300.png has been exported from new svg with correct font "FreeSans".
Shorthand in texts has been replaced: "[#r] the Red Matrix" is now a bold "red[#]matrix" with new logo. I removed "the" for i18n, it should work better with all languages now.
It's the first time I make a pull req that's not just a translation, I've been careful but also triple-check it plz.