fix: playlist more intuitive

fix: p p overwrites playlist

posix: dont use install in makefile

posix: use sh instead of bash

refactor: command substitution

feat: invalid actions

refactor: playlist d, create

fix: update function broken

refactor: simplify get_instances

fix: remove unused code

refactor: more bashisms

refactor: use bash instead of sh

fix: ytfzfctl scrapers install matches ytfzf requirements

docs: add scrapers help

fix: when multiple urls are selected, video-info prints nothing