Added a command to expand filesystem.

How-to-compile-and-build-Stratux-executable.md

@@ -14,6 +14,7 @@ From a remote computer (can be over Wi-Fi or wired Ethernet), login using SSH by
 Or directly on the machine, login with username pi password raspberry
 
     sudo su -
+    raspi-config --expand-rootfs
     cd /root/
     wget https://dl.google.com/go/go1.6.linux-armv6l.tar.gz
     tar -zxvf go1.6.linux-armv6l.tar.gz