nodiscard for certain returned variables

Functions that return multiple variables may have variables that are important or not. There should be a way to flag any return value as nodiscard.

---@return number index
---@return {number:string} list
---@nodiscardall
---@return number nonimportantvariable
function getREALLYImportantList()

I suppose nodiscardall that marks any return above it to be important.
Maybe even @nodiscardabove would workout

该 issue 未指定文件、测试或入口点。首先定位对 LuaDoc @return 注解的处理以及现有的与丢弃相关的诊断，然后明确标记选定返回值的预期范围和语法。完成的标准是实现所选的注解行为，并覆盖返回多个值的函数。