add help text

Author: TomHarrop

tools/tiberius/tiberius.xml

@@ -82,6 +82,21 @@ tiberius.py
 deep learning-based ab initio gene structure prediction tool. 
 It predicts genes from genomic sequence only.
 
+To run Tiberius, you need to provide a FASTA file containing
+the genomic sequences and choose a pre-trained model.
+
+More information about the models is available on the
+Tiberius GitHub
+`page <https://github.com/Gaius-Augustus/Tiberius/tree/main/model_cfg>`__
+
+Tiberius end-to-end integrates convolutional and
+long short-term memory layers with a differentiable HMM layer.
+It can be used to predict gene structures from genomic
+sequences only (ab initio), while matching the accuracy of
+tools that use extrinsic evidence.
+
+
+
     ]]></help>
     <expand macro="citation"/>
 </tool>