ports: add missing README.md files

port/libusb/README.md

@@ -26,4 +26,5 @@ Bluetooth. For this, execute:
 
     sudo nvram bluetoothHostControllerSwitchBehavior=never
 
-You may need to reboot for the change to become active.
+and then reboot to activate the change.
+

port/posix-h4-zephyr/main.c

@@ -129,7 +129,7 @@ int main(int argc, const char * argv[]){
     hci_dump_open("/tmp/hci_dump.pklg", HCI_DUMP_PACKETLOGGER);
 
     // pick serial port
-    config.device_name = "/dev/tty.usbmodem14514411"; // PCA10040 nRF52832 
+    config.device_name = "/dev/tty.usbmodem14514421"; // PCA10040 nRF52832 
 
     // accept path from command line
     if (argc >= 3 && strcmp(argv[1], "-u") == 0){

port/windows-h4/README.md

@@ -0,0 +1,10 @@
+# BTstack Port for Windows Systems with Bluetooth Controller connected via Serial Port
+
+The Windows-H4 port uses the native run loop and allows to use Bluetooth Controllers connected via Serial Port.
+
+Make sure to manually reset the Bluetooth Controller before starting any of the examples.
+
+When running the examples in the MSYS2 shell, the console input (via btstack_stdin_support) doesn't work. It works in the older MSYS and also the regular CMD.exe environment. Another option is to install WinPTY and then start the example via WinPTY like this:
+
+    $ winpty ./hfp_hf_demo.exe
+

port/windows-winusb/README.md

@@ -1,11 +1,12 @@
-# BTstack Port for Windows Systems using the WinUSB Driver
+# BTstack port for Windows Systems using the WinUSB Driver
 
-Although libusb basically works with the POSIX Run Loop on Windows, we recommend to use the Windows-WinUSB port that uses the native run loop and WinUSB API to access a USB Bluetooth dongle.
+The Windows-WinUSB port uses the native run loop and WinUSB API to access a USB Bluetooth dongle.
 
 To allow libusb or WinUSB to access an USB Bluetooth dongle, you need to install a special device driver to make it accessible to user space processes. 
 
 It works like this:
--  Start [Zadig](http://zadig.akeo.ie)
+-  Download [Zadig](http://zadig.akeo.ie)
+-  Start Zadig
 -  Select Options -> “List all devices”
 -  Select USB Bluetooth dongle in the big pull down list
 -  Select WinUSB (libusb) in the right pull pull down list