Mention that Windows users need to install MSVC 2015 redistributable in README.

Author: s3rvac

README.md

@@ -31,7 +31,9 @@ Currently, we support only Windows and Linux.
     * 32b Windows: TBA
     * 64b Windows: TBA
 
-2. Install [MSYS2](http://www.msys2.org/) and other needed applications by following RetDec's [Windows environment setup guide](https://github.com/avast-tl/retdec/wiki/Windows-Environment).
+2. Install [Microsoft Visual C++ Redistributable for Visual Studio 2015](https://www.microsoft.com/en-us/download/details.aspx?id=48145).
+
+3. Install [MSYS2](http://www.msys2.org/) and other needed applications by following RetDec's [Windows environment setup guide](https://github.com/avast-tl/retdec/wiki/Windows-Environment).
 
 3. Now, you are all set to run the decompiler. To decompile a binary file named `test.exe`, go into `$RETDEC_INSTALLED_DIR/bin` and run: