fix broken link in release notes

release_notes/june-2021.md

@@ -5,7 +5,7 @@ Welcome back to the release notes for Live Preview! Download it from the marketp
 ## Improved Embedded Preview UI
 ### Navigation Bar
 Features a new URL bar with the pre-existing navigation and refresh buttons!
-![Navigation Bar](images/june-2021/nav-bar.png)
+![Navigation Bar](images/june-2021/nav-bar.PNG)
 
 ### Link Preview
 When you hover a link, you can now see browser-like link previews.
@@ -31,4 +31,4 @@ If you prefer to have less frequent preview refreshes when editing, configure th
 Here's editing with the 'on save' option!
 ![On Save Refresh](images/june-2021/on-save-demo.gif)
 
-Thanks for reading and stay tuned for more updates. 😀🔧
+Thanks for reading and stay tuned for more updates. 😀🔧