zsh fix standard unbound keys

.zsh-standard-keys

bindkey '^H' backward-delete-char
bindkey '^?' backward-delete-char

for keymap in emacs viins vicmd
do
    bindkey -M $keymap '^[[H' vi-beginning-of-line
    bindkey -M $keymap '^[[F' vi-end-of-line

    bindkey -M $keymap '^[[5~' beginning-of-buffer
    bindkey -M $keymap '^[[6~' end-of-buffer
done

zle -N beginning-of-buffer
zle -N end-of-buffer
function beginning-of-buffer()
{
    case $LBUFFER in *$'\n'*)
        zle beginning-of-buffer-or-history
        return
    esac
    zle beginning-of-line
}
function end-of-buffer()
{
    case $RBUFFER in *$'\n'*)
        zle end-of-buffer-or-history
        return
    esac
    zle end-of-line
}

This adds standard behavior to some keys that zsh leaves unbound by default:

1. Backspace actually works (different terminals send different key codes for it).
2. Home and End jump beginning or end of current line.
3. Page Up and Page Down jump to beginning or end of the current input (different from Home and End on multiline history items).