Changed SGen and SText plugin.xml to integrate into YAKINDU preference page

plugins/org.yakindu.sct.generator.genmodel.ui/plugin.xml

@@ -51,9 +51,10 @@
     <extension
             point="org.eclipse.ui.preferencePages">
         <page
-            class="org.yakindu.sct.generator.genmodel.ui.SGenExecutableExtensionFactory:org.eclipse.xtext.ui.editor.preferences.LanguageRootPreferencePage"
-            id="org.yakindu.sct.generator.genmodel.SGen"
-            name="SGen">
+              category="org.yakindu.sct.ui.preferences.root"
+              class="org.yakindu.sct.generator.genmodel.ui.SGenExecutableExtensionFactory:org.eclipse.xtext.ui.editor.preferences.LanguageRootPreferencePage"
+              id="org.yakindu.sct.generator.genmodel.SGen"
+              name="SGen">
             <keywordReference id="org.yakindu.sct.generator.genmodel.ui.keyword_SGen"/>
         </page>
         <page

plugins/org.yakindu.sct.model.stext.ui/plugin.xml

@@ -50,9 +50,10 @@
     <extension
             point="org.eclipse.ui.preferencePages">
         <page
-            class="org.yakindu.sct.model.stext.ui.STextExecutableExtensionFactory:org.eclipse.xtext.ui.editor.preferences.LanguageRootPreferencePage"
-            id="org.yakindu.sct.model.stext.SText"
-            name="SText">
+              category="org.yakindu.sct.ui.preferences.root"
+              class="org.yakindu.sct.model.stext.ui.STextExecutableExtensionFactory:org.eclipse.xtext.ui.editor.preferences.LanguageRootPreferencePage"
+              id="org.yakindu.sct.model.stext.SText"
+              name="SText">
             <keywordReference id="org.yakindu.sct.model.stext.ui.keyword_SText"/>
         </page>
         <page