P3876 Use Result instead of Remarks for alias template

[eisenwave]

cpp-proposals/src/charconv-ext.cow

Lines 693 to 701 in fdba94a

	\remarks
	Denotes
	\ul{
	\li{\tcode{to_chars_result} if \tcode{T} is \tcode{char},}
	\li{\tcode{u8to_chars_result} if \tcode{T} is \tcode{char8_t},}
	\li{\tcode{u16to_chars_result} if \tcode{T} is \tcode{char16_t},}
	\li{\tcode{u32to_chars_result} if \tcode{T} is \tcode{char32_t}, and}
	\li{\tcode{wto_chars_result} if \tcode{T} is \tcode{wchar_t}.}
	}

The proper [structure.specifications] element for determining types is Result. This is used in many places for type aliases in existing wording.

Consistent with cplusplus/draft#8151