Update metadata in span class reference

Author: Rageking8

docs/standard-library/span-class.md

@@ -1,7 +1,7 @@
 ---
-title: span class (C++ Standard Library)
+title: "span class (C++ Standard Library)"
 description: "API reference for the Standard Template Library (STL) span class, which provides a lightweight view over a contiguous sequence of objects."
-ms.date: "05/28/2020"
+ms.date: 05/28/2020
 f1_keywords: ["span/std::span", "span/std::span::const_pointer", "span/std::span::const_reference", "span/std::span::difference_type", "span/std::span::element_type", "span/std::span::iterator", "span/std::span::pointer", "span/std::span::reference", "span/std::span::reverse_iterator", "span/std::span::size_type", "span/std::span::value_type", "span/std::span::at", "span/std::span::assign", "span/std::span::back", "span/std::span::begin", "span/std::span::data", "span/std::span::empty", "span/std::span::end", "span/std::span::front", "span/std::span::rbegin", "span/std::span::rend", "span/std::span::size", "span/std::span::size_bytes", "span/std::span::operator=", "span/std::span::operator[]"]
 helpviewer_keywords: ["std::span [C++]", "std::span [C++], const_pointer", "std::span [C++], const_reference", "std::span [C++], difference_type", "std::span [C++], element_type", "std::span [C++], iterator", "std::span [C++], pointer", "std::span [C++], reference", "std::span [C++], reverse_iterator", "std::span [C++], size_type", "std::span [C++], value_type", "std::span [C++], assign", "std::span [C++], at", "std::span [C++], back", "std::span [C++], begin", "std::span [C++], data", "std::span [C++], empty", "std::span [C++], end", "std::span [C++], front", "std::span [C++], rbegin", "std::span [C++], rend", "std::span [C++], size", "std::span [C++], size_bytes"]
 dev_langs: ["C++"]