[README.md] Missing information to compile?

[rtek1000]

make BOARD=RPI1
/bin/sh: 1: arm-none-eabi-gcc: not found

• How to install virtualenv
  https://gist.github.com/frfahim/73c0fad6350332cef7a653bcd762f08d

• Getting Started
  https://github.com/micropython/micropython/wiki/Getting-Started

Debian, Ubuntu, Mint, and variants

The following packages will need to be installed before you can compile and run MicroPython:

build-essential
libreadline-dev
libffi-dev
git
pkg-config (required at least in ubuntu 14.04)
gcc-arm-none-eabi
libnewlib-arm-none-eabi

[boochow]

@rtek1000 Thank you for your question.
I didn't include instructions about how to set up the cross-platform development environment since it depends on which platform is used for development.
One of the easiest ways is to use apt on ubuntu:
sudo apt-get install gcc-arm-none-eabi

[gigawatts]

+1 for adding this to the README