message: Update README.md
  Made make instructions more specific
diff: @@ -73,9 +73,10 @@ DateTime class included in this library is a very cool and handy object to manip
  ### Installing using CMake
  ```
  -mkdir build
  -cd build
  -cmake ..
  +mkdir [Debug | Release]
  +cd [Debug | Release]
  +cmake -DCMAKE_BUILD_TYPE=[Debug | Release] ..
  +make
  make install
  ```
  