Update Document Creation Process

- Add proper Build and Makefile files in Source/Doc directory
- Switch preprocessing from pp to m4 which is more supportable across platforms
- Building of documentation is still done manually as needed, but it is now easy to do under either Windows or Linux using provided files

Source/BuildDoc.cmd

@@ -0,0 +1,4 @@
+@echo off
+setlocal
+
+pushd Doc && call Build || exit /b & popd