feat: switch to biome, apply formatting, shellcheck (#227)

* feat: switch to biome, apply formatting, shellcheck
* chore: apply cr comments
* chore: few config tweaks, shellcheck hook now py-based
* chore: lint fixes and pr comments
* chore(lint): megalinter, and other fixes

Signed-off-by: Ismo Vuorinen <ismo@ivuorinen.net>

.prettierignore

@@ -1,16 +0,0 @@
-# vim: ft=gitignore
-.mypy_cache/*
-Brewfile.lock.json
-base/plan
-config/cheat/cheatsheets/community
-config/cheat/cheatsheets/tldr
-config/fzf/*
-config/nvim/*
-config/op/plugins/used_plugins/*
-config/tmux/plugins/*
-config/zsh/*
-lazy-lock.json
-local/bin/antigen.zsh
-local/bin/asdf
-tools/antidote/*
-tools/dotbot*