The "Standard numeric format strings" doc is out of date

[carlossanlop]

From this conversation: dotnet/runtime#71038 (comment)

This documentation is out of date: https://docs.microsoft.com/en-us/dotnet/standard/base-types/standard-numeric-format-strings#general-format-specifier-g

Here's the doc:
https://github.com/dotnet/docs/blob/main/docs/standard/base-types/standard-numeric-format-strings.md

@tannergooding knows the correct values returned by the formatting options.

[eerhardt]

Closing in favor of #29952.