font: use system, dim colors

let's respect users' choice, and emulate the original light touch by
color. this removes the major source of current loaded assets size.
those don't have proper cjk font probably cannot read chinese anyway.
about: fix my english
posts: choosing-distro: adjust package format section
posts: add choosing distro
masthead: lower nav font size
add link to about
sass: adjust avatar position on top bar
sass: make avatar square
about: fix layout
add a short about page
move-to-xdavidwu-link: fix typo
posts: add move-to-xdavidwu-link
kubeadm-psp: add anno for seccomp
update for new domain
change domain
comments: matrix: add matrix: scheme link to rooms
css: comments: reduce size
css: comments: fix avatar shrink and space handling