Improved enunciate documentation

Changes:
- switched to enunciate 2.18 (from 2.17)
- improved storagehub description in the index page (still improvable)
- added missing dependencies from storagehub-model

enunciate.xml

@@ -1,11 +1,19 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <enunciate
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:noNamespaceSchemaLocation="http://enunciate.webcohesion.com/schemas/enunciate-2.14.0.xsd">
-	<api-classes>
-		<!-- Use patterns to exclude classes... e.g. for URI-Resolver <exclude 
-			pattern="org.gcube.datatransfer.resolver.services.DocsGenerator" /> -->
-	</api-classes>
+	xsi:noNamespaceSchemaLocation="http://enunciate.webcohesion.com/schemas/enunciate-2.18.0.xsd">
+	<description>
+		<![CDATA[
+			<h1>StorageHUB</h1>
+			<p>StorageHUB is the service implementing the gCube Workspace feature.</p> 
+			<p>It provides an intermediate layer between the storage and the services 
+			willing to access it.</p> 
+		]]>
+	</description>
+	<code-license>This project is licensed under the EUPL V.1.1 License - see the LICENSE.md file for details.</code-license>
+
+	<!-- Include storagehub-model classes -->
+
 	<modules>
 		<gwt-json-overlay disabled="true" />
 		<php-json-client disabled="true" />
@@ -19,6 +27,7 @@
 			<additional-css
 				file="css/d4science_enunciate_custom.css" />
 		</docs>
+		<jaxrs groupBy="class" disableExamples="false" path-sort-strategy="depth_first" />
 		<swagger basePath="/workspace" />
 	</modules>
 </enunciate>

pom.xml

@@ -32,7 +32,7 @@
 		<warname>storagehub</warname>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-		<enunciate.version>2.17.1</enunciate.version>
+		<enunciate.version>2.18.1</enunciate.version>
 		<maven.compiler.source>17</maven.compiler.source>
 		<maven.compiler.target>17</maven.compiler.target>
 		<java_version>17</java_version>
@@ -428,7 +428,15 @@
 				<groupId>com.webcohesion.enunciate</groupId>
 				<artifactId>enunciate-maven-plugin</artifactId>
 				<version>${enunciate.version}</version>
-				<configuration></configuration>
+				<configuration>
+					<!-- Include storagehub-model classes -->
+					<sourcepath-includes>
+						<sourcepath-include>
+							<groupId>org.gcube.common</groupId>
+							<artifactId>storagehub-model</artifactId>
+						</sourcepath-include>
+					</sourcepath-includes>
+				</configuration>
 				<executions>
 					<execution>
 						<id>assemble</id>