Provide correct default for scroll_history
Provide correct default for scroll_history

When implementing fallback to the default value with an u32 you will get
0 as the default value.

However the default scrollback value is 10_000. A custom deserializer
has been implemented which automatically falls back to the correct
default value.

jwilm/alacritty,alacritty/alacritty,jwilm/alacritty,jwilm/alacritty,alacritty/alacritty,jwilm/alacritty