organize code into core and themes
add keybindings space = forward, backspace = back

- add keybindings for space and backspace
- optimize conditions
- rename 'Pop-up' button to 'Launch'
- add keybinding 'o' to launch pop-up from onstage shell
change title of onstage shell
whitespace
swap core and default theme stylesheets
automatically add progress bar element
formatting
only retrieve notes on slide transition
add aspect ratio support (default to 4:3)
add watermelon theme
add notes to default theme
add optional highlight.js include block
add support for nested details in notes
add additional transitions
move slide flipping defaults to core styles
update notes
remove aria-selected from last incremental, bind j and k
bind j and k
ignore decks/ directory
script to export slides to PNGs and a PDF