v1.0.0

No more zerover here! It's small, simple, and "stable", I don't imagine I'll add
much more other than minor tweaks or any bug fixes.

Added

• Version indicator
• Confirmation "dialog" on clear button
• Checklist switcher - buttons at the top, we now support persisting three separate checklists! Wow!
• Unicode arrows to swap buttons
• Placeholder text to new item textbox

Fixed

• Add button not clearing new item textbox
• Add button margins