Update README.md

Author: hvandermarel

README.md

@@ -1,2 +1,24 @@
-# IGP
-Integrated Geodetic Processing
+# Integrated Geodetic Processing (IGP)
+
+**Release 1.0b1 d.d. December 2nd, 2024**
+
+This repository contains version 1.0 of the NAM Integrated Geodetic Processing
+software (IGP).
+
+The main folder structure is
+
+| folder       | content                                      |
+| ------------ | ---------------------------------------------|
+| igpsoftware  | actual Matlab software                       |
+| igptemplates | processing templates (Matlab scripts)        |
+| igpprojects  | processing results (empty)                   |
+| igpdata      |  staging area for the input files (empty)    |
+
+Actual processing is done within igpprojects. To start a new project in igpproject:
+
+1. copy the raw data files to `igpdata`
+2. copy one of the template folders from `igptemplates` to `igpprojects`
+3. modify the copied template in `igpprojects`
+4. process the project in `igpprojects`
+
+See the IGP User Manual for more instructions.