Added Subtraction, Multiplication, Division

they were all easy, everything after itoa was easy so far.
also made github repo and the readme has my todo stuff too.

Addition

yeah it can do addition now, but 1h 24m to make that?
hell NO.

most of the time went on a stupid Integer to ASCII conversion function it was so hard to implement but i did it at the end

the calculator lacks hella checks tho, you can do “hi + hello” and get 620280 (yes literally idk how)

made atoi

ASCII to integer conversion
i am an idiot so i accidenttely said “itoa” in git commit T_T (integer to ASCII)

yeah not much to show right now, just took almost an hour debugging and trying to fix the the loop

screenshot shows i entered those values which is taken as ASCII and the output from reading the num1 and num2 bytes it prints those as numbers

made those CLI messages and input reading
basic write and read syscalls