More extended readme

README.md

@@ -2,4 +2,19 @@
 
 This is a small test area how to edit SQLite databases and update some values according to their value.
 
+## Files
 
+```
+├── script.sh
+├── sql
+│   ├── create_db.sql
+│   ├── insert_data.sql
+│   └── show_all.sql
+└── test.db
+```
+
+- `script.sh`: Small script to executre commands inside the sql-files (see `sql/`)
+- `sql/`
+    - `create_db.sql`: creates the small test database
+    - `insert_data.sql`: insert some fictive test values into the database
+    - `show_all.sql`: Shows all the data inside the database from table customers