Add info about vcpkg package

Author: unterumarmung

README.md

@@ -56,6 +56,8 @@ void foo()
 ## Integration
 Since it's a header only library, you need just copy `fixed_string.hpp` to your project.
 
+If you are using [vcpkg](https://github.com/Microsoft/vcpkg/) on your project for external dependencies, then you can use the [**fixed-string** package](https://github.com/microsoft/vcpkg/tree/master/ports/fixed-string).
+
 ## Compiler compatibility
 * GCC >= 7.3
 * Clang >= 5