Rewrote, condensed

all previous actions combined into the main class, to be separated
later, when i actually figure out how to choose a file when i’m trying
to read—how do i address a file i opened? what do i call it? how do i
make a FileReader for it? i’ll come back to it later… but this is just
a shorter version of all that other stuff i previously had, plus
beginning to add data.
._.

i just wanted to sync one file :c see the previous commit.