Simplify encoding API and use variant instead of any for the data type

Author: Jim Porter

README.md

@@ -1,14 +1,15 @@
 # bencode.hpp
 
-**bencode.hpp** is a small, header-only C++ library for parsing
+**bencode.hpp** is a small, header-only C++ library for parsing and generating
 [bencoded](https://en.wikipedia.org/wiki/Bencode) data.
 
 ## Requirements
 
-This library requires a C++11 compiler, plus either
-[Boost](http://www.boost.org/) 1.23+ or the [Library Fundamentals
-TS](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4480.html) (for
-the `any` type). The tests additionally require a C++14 compiler and
+This library requires a C++11 compiler and [Boost](http://www.boost.org/)
+1.23+. If your standard library includes the [Library Fundamentals
+TS](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4480.html)
+(specifically the `string_view` type), bencode.hpp will used that as well. In
+addition, the tests require a C++14 compiler and
 [mettle](https://jimporter.github.io/mettle/).
 
 ## Installation