[#530] Add tip for underlines and italics

Author: prmr

src/org/jetuml/JetUML.properties

@@ -176,7 +176,7 @@ warning.version.title=Diagram Version Migration
 files.image.name=Image Files
 tips.jsons.directory=/tips
 tips.images.directory=/tip_images
-tips.quantity=38
+tips.quantity=39
 dialog.tips.button.next.text=Next Tip
 dialog.tips.button.previous.text=Previous Tip
 dialog.tips.button.close.text=Close

tipdata/tip_images/tip39.png

@@ -0,0 +1,12 @@
+{ 
+  "title": "Underlining or Italicizing Text",
+  "content": [ 
+    { "text": "To show a line of text in italics, surround it with forward slashes (e.g., /abstract/). To show a line of text underlined, surround it with underscores (e.g., _underlined_)."},
+    { "image": "tip39.png"}
+  ],
+  "tags": [
+    { "topic": "creating"},
+    { "level": "intermediate"},
+    { "diagram": "class"}
+  ]
+}