Put NetHook2 in it's own directory + add small readme

tools/NetHook2/README.md

@@ -0,0 +1,17 @@
+NetHook2
+===================
+
+This tool is used for reverse-engineering of Steam client. It's capable of hooking and recording network traffic sent/received by the client. If you're not trying to implement missing SK2 functionality in ASF, then please do not proceed.
+
+1. Launch Steam client
+2. Execute ```hook.bat```
+3. Reproduce the functionality you're trying to add
+4. Execute ```unhook.bat```
+5. Use ```NetHookAnalyzer2.exe``` for analyzing recorded log (which can be found in your Steam directory)
+
+- Source of the ```NetHook2.dll``` can be found **[here](https://github.com/SteamRE/SteamKit/tree/master/Resources/NetHook2)**
+- Source of the ```NetHookAnalyzer2.exe``` can be found **[here](https://github.com/SteamRE/SteamKit/tree/master/Resources/NetHookAnalyzer2)**
+
+===================
+
+There is absolutely no guarantee that this will even work for you, not to mention the consequences from hooking the external DLL into steam client. You're on your own.