date update: add format descriptions

[forivall]

Command

date

Version

9.10

Release

n/a

Changelog

No response

Anything else?

The completer for date is missing support for the format strings.

This is less about a new version and more about adding completion support for the format descriptors. the zsh completer for date has completion for the formatting, and so for now, i simply added it to my excludes list, as zsh provides better completion natively via https://github.com/zsh-users/zsh/blob/master/Completion/Unix/Type/_date_formats and https://github.com/zsh-users/zsh/blob/master/Completion/Unix/Type/_date