Wezterm: hot key doesn't work reliably

[tuananh]

Describe the bug

A clear and concise description of what the bug is.

Environment (please complete the following information):

• OS: macOS big sur
• Version: 20201031-154415-9614e117

To Reproduce

```local wezterm = require 'wezterm'
return {
font = wezterm.font_with_fallback({"Cascadia Code PL", "Operator Mono"},
{bold = false}),
font_size = 14.0,
color_scheme = "ayu Light",
hide_tab_bar_if_only_one_tab = false,
disable_default_key_bindings = false,
keys = {
{key = "k", mods = "CMD", action = "ClearScrollback"},
{key="w", mods="CMD",action=wezterm.action{CloseCurrentPane={ confirm=false}}},
{key="d", mods="CMD", action=wezterm.action{SplitVertical={ args={"top"}}}},
{key="d", mods="CMD|SHIFT", action=wezterm.action{SplitHorizontal={ args={"top"}}}}
}
}

```

however, cmd+shift+d combo fails to work reliably. it works sometimes and most of the time, it doesn't

[wez]

Take shift out of the mods and uppercase the key like this:

{key="D", mods="CMD",

[tuananh]

Thank you!

[wez]

This part of the config:

SplitHorizontal={ args={"top"}}

tells wezterm to run top in the split.

I think you want just: SplitHorizontal={} if you want it to run the default program. If it doesn't like the empty {} then you could try: SplitHorizontal={Domain="CurrentPaneDomain"}