profile: remove platform-specific link generators

those are dumb when you have a generic one
links: simplify sa usage
fa: fav4-ify
page__meta: fa: always fixed width

ruby: depends on matrix, for classifier-reborn, for ruby 3.1
un-vendor lunr, use npm to copy
js: cleanup, un-webpackify, trim unused
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
nav: add about
add link to about
sass: adjust avatar position on top bar
sass: make avatar square
add avatar
about: fix layout
add a short about page
move-to-xdavidwu-link: fix typo