Copy over some MSDN code into tcp_client.h. Beginning of project

build.bat

@@ -0,0 +1,9 @@
+@ECHO off
+SET flags=-Od -ZI
+IF "%1" == "release" (
+    SET flags=-O2
+)
+@echo on
+SET srcs=src\*
+mkdir bin obj
+cl %srcs% Ws2_32.lib -I inc %flags% -std:c++20 -MP -Fo:obj\\ -Fe:bin\\