The doc is great! Hoewever some areas are still missing.
C++11 intoduced raw string literals: https://en.cppreference.com/w/cpp/language/string_literal

It is useful in many different areas, like strings with quotes, multiline strings and for example windows paths without escaping backslashes:

const char win_path[] = R"(c:\some\unescaped\path)";

The same cppreference link also mentions u8/u16/u32 literals, but I'm not sure that their addition is major enough to include in a high-level list.