update windows build instructions

include shell commands to make it easier to install the correct dependencies
make a note about Java
remove restriction on installing LCM before using it; that's no longer necessary since statically linking more stuff

WinSpecific/README.md

@@ -1,16 +1,28 @@
 # LCM port to Windows
 
-We currently support and test on an [MSYS2](https://www.msys2.org/) MINGW64 environment. Please
-reference the GitHub actions that test on Windows in this project for packages necessary to build
-LCM in an MSYS2 environment.
+## Core Dependencies
+
+We currently support and test on an [MSYS2](https://www.msys2.org/) MINGW64 environment. To install
+the necessary dependencies, you can run:
+
+```shell
+pacman -S pactoys git make
+pacboy -S git make toolchain cmake glib2 gtest python-pip
+```
+
+## Java
+
+The above does not result in an environment with Java. If you need the Java-dependent components of
+LCM, please see the [openjdk docs](https://openjdk.org/groups/build/doc/building.html) in order to
+install a JDK.
+
+## Other Notes
 
 There are a few things to watch out for:
 
-1. Before running any LCM executables locally, LCM should be installed. Otherwise Windows will not
-   be able to load the built DLLs.
-2. When installing LCM, CMake defaults to the usual Windows directories rather than the MSYS2
+1. When installing LCM, CMake defaults to the usual Windows directories rather than the MSYS2
    environment. You can use CMake's `--prefix` option when installing to override this.
-3. If there is an installation of Python on the system in addition to the MSYS2 version, cmake may
+2. If there is an installation of Python on the system in addition to the MSYS2 version, cmake may
    pick it up instead. If that is the case, it may be necessary to set
    `-DPython_FIND_REGISTRY=NEVER` or [one of the other
    hints](https://cmake.org/cmake/help/latest/module/FindPython.html#hints) when configuring a build