Tidied up the main README.

README.md

-# Tree Edit Distance similarity join - datasets scripts
+# Datasets for tree edit distance experiments
 
-This repository contains all resources to download and process the datasets for
-tree similarity join experiments.
+This repository contains all resources to acquire datasets for experimenting
+on tree edit distance algorithms.
 
 **We do not store the datasets**, only the scripts to obtain and prepare them.
 
 ## Datasets description
 
 Currently we support the following datasest:
-- **bozen** - Bozen streets
-- **dblp** - DBLP
-
-The details about each dataset can be found in the corresponding README files.
+- **Bolzano** - Residential addresses in the city of Bolzano.
+- **DBLP** - Bibliographic XML data.
+- **Python** - Abstract syntax trees of Python source code in JSON.
+- **Sentiment** - Semantic trees of movie reviews in the PennTreeBank format.
+- **Swissprot** - Protein sequence data in XML.
+
+The details about each dataset can be found in the README files in the
+datasets subdirectories.
 
 ## Repository organisation