Add first draft of Windows build instructions.

diff --git a/win32/README.txt b/win32/README.txt
new file mode 100755 (executable)
index 0000000..01644c3
--- /dev/null
+++ b/win32/README.txt
@@ -0,0 +1,2 @@
+Hello, and welcome to the Windows build instructions for asdcplib.\r
+\r