Update readme and make it clear that python 3.10 is needed

README.md

@@ -1,3 +1,13 @@
-# invent
+# Invent
 
-A dead simple docker image scanner
+Invent is a dead simple docker image scanner. It will try to scan one or more docker image that it can reach with docker pull and output information about installed packages, operating system and docker inspect information.
+
+## Usage
+```
+  ./scanner.py --images debian:latest alpine:latest | jq .
+```
+
+The above command will download latest debian and alpine images from docker hub and scan them, and output the information in json format.
+
+## Requirements
+The scanner needs python 3.10 and docker installed.

scanner.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python3
+#!/usr/bin/env python3.10
 import argparse
 import json
 import subprocess