HOWTO : how to build pipy on ubuntu20

A quick guide , it works on my ubuntu-arm64 (UTM VM, ubuntu20 arm64 minimal install with ssh-server) on M1 :

1. clone pipy : git clone https://github.com/flomesh-io/pipy.git
2. install build-essential : sudo apt install build-essential -y
3. install clang & cmake : sudo apt install clang cmake -y
4. install nodejs16 : 4.1 curl -sL https://deb.nodesource.com/setup_16.x | sudo bash - 4.2 sudo apt -y install nodejs
5. build pipy : 5.1 cd pipy 5.2 ./build.sh

Put all together:

git clone https://github.com/flomesh-io/pipy.git
sudo apt install build-essential -y
sudo apt install clang cmake -y
curl -sL https://deb.nodesource.com/setup_16.x | sudo bash -
sudo apt -y install nodejs
cd pipy
./build.sh
bin/pipy -v