add readme

README.md

-# tla2bAST
+TLA2B
+=====
+
+This project contains a translator from TLA+ to B for animation and validation of TLA specifications using ProB.
+
+The following article describes the translation:
+Dominik Hansen and Michael Leuschel.
+Translating TLA+ to B for Validation with ProB.
+Proceedings IFM 2012. LNCS, vol 7321. pages 24-38. 2012.
+[Link](https://doi.org/10.1007/978-3-642-30729-4_3)
+
+More details about using TLA2B can be found on the [ProB web pages](https://prob.hhu.de/w/index.php?title=TLA).
 
 [![GitLab CI](https://gitlab.cs.uni-duesseldorf.de/general/stups/tla2bAST/badges/master/pipeline.svg)](https://gitlab.cs.uni-duesseldorf.de/general/stups/tla2bAST/pipelines)