Update README.md

Author: mdesalvo

README.md

@@ -2,21 +2,21 @@
 
 RDFSharp is a modular .NET library made up of 3 layers: 
 
-<b><a href="https://github.com/mdesalvo/RDFSharp/releases/download/v3.14.0/RDFSharp.Model-3.14.0.pdf">RDFSharp.Model</a></b>
+<b><a href="https://github.com/mdesalvo/RDFSharp/releases/download/v3.15.0/RDFSharp.Model-3.15.0.pdf">RDFSharp.Model</a></b>
 <ul>
     <li>Create and manage <b>RDF models</b> (resources, literals, triples, graphs, namespaces, datatypes, ...)</li>
     <li>Exchange them using standard <b>RDF formats</b> (N-Triples, TriX, Turtle, RDF/Xml)</li>
     <li>Create and validate <b>SHACL shapes</b> (shape graphs, shapes, targets, constraints, reports, ...)</b></li>
 </ul>
 
-<b><a href="https://github.com/mdesalvo/RDFSharp/releases/download/v3.14.0/RDFSharp.Store-3.14.0.pdf">RDFSharp.Store</a></b>
+<b><a href="https://github.com/mdesalvo/RDFSharp/releases/download/v3.15.0/RDFSharp.Store-3.15.0.pdf">RDFSharp.Store</a></b>
 <ul>
     <li>Create and manage <b>RDF stores</b> for context-aware modeling of RDF data (contexts, quadruples, ...)</li>
     <li>Exchange them using standard <b>RDF formats</b> (N-Quads, TriX, TriG)</li>
     <li>Pick a store <a href="https://github.com/mdesalvo/RDFSharp.Extensions">extension</a> to save and query big RDF data on many supported providers</li>
 </ul>
 
-<b><a href="https://github.com/mdesalvo/RDFSharp/releases/download/v3.14.0/RDFSharp.Query-3.14.0.pdf">RDFSharp.Query</a></b>
+<b><a href="https://github.com/mdesalvo/RDFSharp/releases/download/v3.15.0/RDFSharp.Query-3.15.0.pdf">RDFSharp.Query</a></b>
 <ul>
     <li>Create and execute <b>SPARQL queries</b> on graphs, stores, federations and SPARQL endpoints</li>
     <li>Create and execute <b>SPARQL operations</b> on graphs, stores and SPARQL UPDATE endpoints</li>