add *.configsymlink convention for ~/.config/ dotfiles

[drewwells]

Introduces install_config_dotfiles() which mirrors the existing *.symlink -> $HOME behavior, but links *.configsymlink files into $HOME/.config/ for tools that follow XDG config conventions.

[matthiasseghers]

I did a similar approach, but instead of using a *.configsymlink filename convention, I match any file under topic/config/ and symlink each file individually into ~/.config//, preserving subdirectory structure. This means nested configs like nvim/config/lua/plugins.lua → ~/.config/nvim/lua/plugins.lua work automatically with no extra convention needed.

install_config_files () {
  info 'installing ~/.config files'

  while IFS= read -r src; do
    # Derive topic from the first path component after DOTFILES_ROOT
    local rel="${src#"$DOTFILES_ROOT"/}"
    local topic="${rel%%/*}"
    # Derive path within config/ (strip <topic>/config/)
    local subpath="${rel#"$topic"/config/}"
    local dst="$HOME/.config/$topic/$subpath"
    mkdir -p "$(dirname "$dst")"
    link_file "$src" "$dst"
  done < <(find -H "$DOTFILES_ROOT" -mindepth 3 -type f -path '*/config/*' -not -path '*.git*' -not -name '*.symlink')
}