added minimal usage in readme

readme.md

@@ -11,3 +11,26 @@ This project is a little tool written in python and QT to change and view IPTC i
 
 ## Creating binaries with PyInstaller
 run ```pyinstaller Graphis_pyinstaller.spec``` to create an executable software package graphis_XX.
+
+## Usage
+The tool aims to add or manipulate IPTC image regions. Defined geometries within the IPTC image regions are
+Circles/Rectangles/Polygons. These geometries can be created/moved/changed. Only geometries within
+the image area are allowed as well polygons have to be valid to be saved. Additional extra meta information
+can be stored for each image region. 
+
+While currently only fixed meta fields of the image region can be edited, all meta information wihtin the
+image regions can be shown with the tabs on the right side called "View region info" to show the region info of the current selected geometry
+and "All region info" which shows all image region within the current image.
+
+Currently, all images supported by "PySide6" and "rawpy" can be imported. For importing and saving metadata 
+"exiftool (https://exiftool.org/)" is used.
+
+Right-Click:    Create new image region. Polygon is finished by left click.
+                Moving geometries. Change geometrie by right-click on the nearest vertices or the circle border
+
+Changes are submitted to the project's sqlite file. Geometry creation/changes are submitted to the database immediately,
+while metadata changes on the right have to be submitted by the save button
+To update the image's metadata use the menu on top "save image regions to file"
+
+
+![ ](doc/images/main_window.jpg)