update readme with windows build instructions

README.md

@@ -24,3 +24,20 @@ We supply an arm-pie version of tor in `android/libs/armeabi-v7a` with the name
 
     qtdeploy -docker build android
     adb install deploy/android/build-debug.apk
+
+## Windows
+
+- Download and install [QT](https://www.qt.io/download) Open Source edition
+- Go to My Computer - Right Click on This PC - Advanced System Settings -  Environment Variables
+    - New - QT_DIR = C:\Qt (or wherever you have it installed)
+    - New - QT_VERSION = 5.12.1 (because I picked 5.12.1)
+    - Edit the Path Variable and Add C:\Qt\Tools\mingw530_32\bin
+- Install [MSYS2](https://www.msys2.org/) (Bash shell for windows)
+- Install [Go](https://golang.org/) and make sure it's in the PATH, and add your GOPATH/bin to the PATH
+- Setup therecipe/qt (instructions https://github.com/therecipe/qt/wiki/Installation-on-Windows)
+    - `go get -u -v github.com/therecipe/qt/cmd/...`
+    - `qtsetup` (Can take around an hour?)
+
+If all that is done, then check out cwtch.im/ui and run `qtdeploy` in the root of it.
+
+Currently you will need to manuall run tor first before running cwtch.im/ui