fix: replace execute-kbd-macro with actual isearch commands

The keys might not be bound to what we think they're bound too.
fix: add 2nd argument to signal
fix: correct keybindings for isearch

Both quit-chord-key-1 and 2 should call quit-chord:isearch-exit-chord
refactor: replace colon with dash for consistency
chore: improve docstrings
fix: remove args from isearch-exit workers

The args were originally required because I had declared an interactive
form that required arguments.
chore: fix checkdoc errors