Update README.md

README.md

 ade-xjc
 =======
 
-XML schema binding compiler for CityGML ADEs
+ade-xjc is a command line tool and wrapper for the XML Schema binding compiler `xjc` shipped with [JAXB](https://jaxb.java.net/). ade-xjc compiles arbitrary CityGML Application Domain Extension (ADE) Schemas to a set of corresponding JAXB classes to be used with citygml4j. 
+
+License
+-------
+ade-xjc is free software under the [GNU LGPL Version 3.0](http://www.gnu.org/licenses/lgpl.html). See the `LICENSE.txt` file for more details.
+
+Contributing
+------------
+* To file bugs found in the software create a GitHub issue.
+* To contribute code for fixing filed issues create a pull request with the issue id.
+* To propose a new feature create a GitHub issue and open a discussion.
+
+Building
+--------
+ade-xjc depends on JRE 7 or higher. The project uses [Apache Ant](http://ant.apache.org/) as the build tool. To build the program, run the `build.xml` file from the root of the repository with `dist` as target. 
+
+    % ant dist
+
+This will create a folder `ade-xjc-<version>` with the following subfolders:
+* `license` -- license information
+* `sample` -- a sample CityGML ADE that can be compiled with ade-xjc
+* `schemas` -- the official CityGML, GML and xAL schemas
+
+Compiling a CityGML ADE Schema
+------------------------------
+ade-xjc is a command line tool. In order to launch it, open a shell environment and navigate to the folder where you built the program. The command below runs ade-xjc and compiles the ADE Schema `CityGMLADE.xsd` to JAXB classes.
+
+    % java -jar ade-xjc.jar /home/user/ade/CityGMLADE.xsd
+
+To control the compilation process, ade-xjc offers the following program arguments.
+
+|Argument | Description
+|------|----------
+|`binding <fileName>` | An optional JAXB binding file to control the schema compilation
+|`clean` | Cleans the output folder before compilation
+|`help`, `h` | Prints a help message to the console
+|`non-strict` | Per default, ade-xjc terminates with an error if the contents of the `schemas` subfolder has been changed in order to ensure deterministic compilation results; use this argument to force ade-xjc to continue
+|`output <folderName>` | Target folder where to create the JAXB classes (default: `src-gen`)
+|`package <packageName>` | Name of the Java package to be used for the JAXB classes (default: `ade`)
+|`version` | Prints version information to the console
+
+Note that the ade-xjc binding compiler requires that your ADE schema points to the official CityGML and GML schemas provided in the subfolder `schemas`. So please adapt all `<xs:import>` statements in your ADE schema accordingly before launching ade-xjc.
+
+Using the compiled JAXB classes
+-------------------------------