message: Tidy up README.md build instructions
  fix
diff: @@ -112,10 +112,13 @@ Xcode project files using CMake by executing these commands from
  the root of the repository:
  ```
  +mkdir bin
  cd bin
  cmake .. # for 32-bit Windows builds
  cmake -G Xcode .. # for Apple Xcode builds
  +cd ..
  +mkdir bin64
  cd ../bin64
  cmake -G"Visual Studio 14 2015 Win64" .. # for 64-bit Windows builds (VS2015)
  cmake -G"Visual Studio 15 2017 Win64" .. # for 64-bit Windows builds (VS2017)
  @@ -137,8 +140,8 @@ The files in the repository are laid out thusly:
  ```
  ./
  - bin/ Holds executables and project files
  - bin64/ Holds 64-bit Windows executables and project files
  + bin/ Create this to hold executables and project files
  + bin64/ Create this to hold 64-bit Windows executables and project files
  doc/ Source code and scripts for the documentation
  include/ Add this to your compiler includes
  beast/
  