extend documentation

README.md

 # Keycloak SAML2 metadata feed importer
 
-config
+# requirements
+Python3.10+
+(optional) an external database, to keep track of the syncs, if there is no external DB, sqlite has to be selected 
+## use
+install the required Python packages
+```bash
+pip install -r requirements.txt
+```
+prepare the configuration as mentioned below
+
+run the sync script with
+```bash
+./main.py
+```
+
+## configuration
+### Environment variables
  - SAML2_METADATA_URL (e.g. https://eduid.at/md/aconet-registered.xml) 
  - KEYCLOAK_URL  (url to Keycloak instance)
  - KEYCLOAK_REALM (Keycloak realm)
  - KEYCLOAK_USER  (Keycloak user)
  - KEYCLOAK_PASSWORD (Keycloak users password)
  - DB_TYPE (postresql, mysql or sqlite)
+
+for external datbases
  - DB_USER (database user)
  - DB_PASSWORD (database password)
  - DB_HOST (dbms host)
  - DB_PORT (dbms port)
- - DB_DATABASE (database )
\ No newline at end of file
+ - DB_DATABASE (database )
+
+### mappings
+edit ./attribute_mapping.json, key is the SAML2 attribute, value is the keycloak user attribute
+
+### blacklist IDPs and or SPs
+edit blacklist.json , for SPs list the clientId for IDPs the entityIds
\ No newline at end of file

main.py

-import hashlib
+#!/usr/bin/env python3
+# import hashlib
 import json
 import os
 import sqlite3
 from datetime import datetime
-from pprint import pprint
 
 import database