Added missing info to the Windows README

Win32/README.txt

@@ -517,7 +517,7 @@ be included.
 
 Appendix B - Installing Heimdall Suite from Source
 
-    Heimdall and Heimdall Frontend both utilise the CMake for managing the build
+    Heimdall and Heimdall Frontend both utilise CMake for managing the build
     process. CMake can generate files for various build systems including GNU
     Make and Visual Studio. However, official packages are compiled with GNU
     Make and MinGW-W64 GCC/G++.
@@ -533,7 +533,7 @@ Appendix B - Installing Heimdall Suite from Source
     2. After installing MSYS2 a command prompt will launch, enter:
 
         Pacman -Syu
-        Pacman -S mingw-w64-x86_64 mingw-w64-x86_64-clang mingw-w64-x86_64-cmake mingw-w64-x86_64-make mingw-w64-x86_64-qt5-static
+        Pacman -S mingw-w64-x86_64 mingw-w64-x86_64-clang mingw-w64-x86_64-cmake mingw-w64-x86_64-libusb mingw-w64-x86_64-qt5-static make
 
     3. Add the MinGW-W64 binaries to your PATH environment variable: