readme: update README.md

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
Change-Id: I14ac853a194d75492887e7830cb68f7e2d6da9b3

README.md

@@ -1,8 +1,29 @@
 # ODROID-STAMPER
 
-**ODROID-STAMPER** is a shell script tool to generate Ubuntu OS image for ODROID SBCs, currently it only support ODROID-XU4 and ODROID-N2.
+**ODROID-STAMPER** is a tool to build a minimal Ubuntu image to run on Hardkernel's ODROID SBCs.
 
-    $ sudo apt install git wget dialog pv lynx
-    $ git clone https://github.com/tobetter/odroid-stamper.git
-    $ cd odroid-stamper
-    $ sudo ./odroid-stamper
+## Supported boards:
+ - ODROID-N2
+ - ODROID-XU4
+ - ODROID-C2
+ - ODROID-C4
+ - ODROID-GO2
+ ## Supported Ubuntu Distro version
+ - Ubuntu Bionic Beaver (18.04)
+ - Ubuntu Disco Dingo (19.04)
+ - Ubuntu Focal Fossa (20.04)
+
+# Installing a package on Ubuntu.
+> $ sudo add-apt-repository ppa:tobetter/ppa \
+$ sudo apt-get update \
+$ sudo apt install odroid-stamper \
+$ mkdir work \
+$ cd work \
+$ sudo odroid-stamper
+
+# Installing from a git source tree
+> $ sudo apt install git wget dialog pv lynx \
+$ git clone https://github.com/tobetter/odroid-stamper.git \
+$ cd odroid-stamper \
+$ export ODROID_STAMPER_CHECKOUT=$PWD \
+$ sudo ./odroid-stamper