Update Readme Win build details

README.md

@@ -271,7 +271,7 @@ since it will usually contain spaces, making the build fail.
         make
 
 8. Look in the top level source directory and double-click the setup file to
-   start installing Purr Data on your system.
+   start installing Purr Data on your system or run `./"setup file name"` in MSYS2 shell.
 
 #### Windows 64-bit Using msys2
 
@@ -279,6 +279,18 @@ The instructions are exactly the same as for the 32 bit build (see above), but t
 
 - Install the mingw64 packages for the dependencies. See the i686 packages listed under dependencies above, and replace i686 with x86_64 in the package names when installing.
 
+        pacman -S autoconf automake git libtool \
+          make mingw-w64-x86_64-dlfcn mingw-w64-x86_64-fftw \
+          mingw-w64-x86_64-fluidsynth \
+          mingw-w64-x86_64-SDL2 \
+          mingw-w64-x86_64-ftgl mingw-w64-x86_64-fribidi \
+          mingw-w64-x86_64-ladspa-sdk mingw-w64-x86_64-lame \
+          mingw-w64-x86_64-libsndfile mingw-w64-x86_64-libvorbis \
+          mingw-w64-x86_64-lua mingw-w64-x86_64-toolchain \
+          mingw-w64-x86_64-libjpeg-turbo \
+          mingw-w64-x86_64-speex \
+          rsync unzip wget
+
 - Use the MSYS2 MinGW 64-bit shell (rather than the 32-bit shell) to do the build.
 
 ### Code of Conduct