Reading data sheet is the worst. The dullest thing I've ever done. Though, there's one main thing you can get from it - names and purpose of pins of controller. And that lead me to a thought...
Quick reminder: in assignment 6 (pre-evaluation edition, press the button there to see my struggles) I redesigned hello.ftdi.44.echo board and added a button and an RGB led to it
I totally messed up with pins! Damn it! I've sent two out of three outputs of led to the GND. (that's also the reason why I had to replace nice smd led to lame regular led). Also I haven't add a resistor before the diode so it'll live shorter and also connected the led directly to the button which doesn't allow led to glow while the button is not pressed. Well, I'll make a lesson out of it.
Pins of ATtiny44
Flaws of my board
Using pinout, connect pcb to adruino like this:
Then, follow this steps
https://raw.githubusercontent.com/damellis/attiny/ide-1.6.x-boards-manager/package_damellis_attiny_index.json
and paste it into additional board manager and apply settings