ext/jotdown: upgrade 0.3.0 -> 0.3.2
www: add png favicon

some clients do not support svg favicons
404: fix missing favicon
workspace: use new resolver
www: conditionally add blockquote css
www: conditionally add media css
www: conditionally add toc css
blog: link to hn discussions in notes
www: add note divs
blog h1x-net: note name of DHP
blog h1x-net: describe video more
blog h1x-net: note name and value of d constant
blog h1x-net: note key exchange is Diffie-Hellman
blog: add h1x-net
blog common.mk: support graphviz
gen: add gdbprompt highlight syntax
gen: add video gen_elem
gen: use <details>, <summary> tags for toc
www: specify nested ul markers
www: impl side-by-side divs

allow letting elements be placed side-by-side if there is enough
horizontal space