Add syntaxhighlighting to the MessageSourceSheet

imports/NeoChat/Menu/Timeline/MessageSourceSheet.qml

@@ -5,6 +5,7 @@
 import QtQuick 2.15
 import QtQuick.Controls 2.15
 
+import org.kde.syntaxhighlighting 1.0
 import org.kde.kirigami 2.15 as Kirigami
 
 Kirigami.OverlaySheet {
@@ -16,9 +17,16 @@ Kirigami.OverlaySheet {
     }
 
     TextArea {
+        id: sourceTextArea
         text: sourceText
         readOnly: true
         wrapMode: Text.WordWrap
+
+        SyntaxHighlighter {
+            textEdit: sourceTextArea
+            repository: Repository
+            definition: "JSON"
+        }
     }
 }