Readme updated

README.md

@@ -1,6 +1,12 @@
 # Alpine Raspberry PI
 
-This is a system install of Alpine linux for Raspberry Pi 3B, 3B+ and 4 image ready to burn to an SD card via [balenaEtcher](https://www.balena.io/etcher/) (there's no need to gunzip image).
+This is a system install of Alpine linux for Raspberry Pi 2B, 3B, 3B+ and 4 image ready to burn to an SD card via [balenaEtcher](https://www.balena.io/etcher/) (there's no need to gunzip image).
+
+If you prefer the command line, you can use `dd` and `gzip`:
+
+```shell
+gzip -dc /path/to/your/image.gz | sudo dd bs=4M of=/dev/sdX
+````
 
 The image automatically setup and configures:
 
@@ -13,3 +19,10 @@ The image automatically setup and configures:
 * swap
 * openssh server
 * root partition auto-expand on first boot
+* docker
+* portainer
+
+## Why this project?
+I wanted a board where all the software on it is containerized and easy to restore.
+
+Also, with [Portainer](https://www.portainer.io/), I can keep the entire system under control with a web GUI.