updated screenshot link and image to reflect current plugin version (#66)

* [fix] updated screenshot link and image to reflect current plugin version #62

replaced outdated screenshot.png with an updated screenshot.jpg showcasing the latest plugin interface. updated the readme to link to the new image, fixing the broken link and ensuring the documentation reflects the current version of the plugin.

* [fix] updated screenshot link in readme.md

replaced the link of screenshot with an absolute link, so the image will be displayed correctly in obsidian plugin store.

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Co-authored-by: Philipp Dalheimer <philipp.dalheimer@1und1.de>

README.md

@@ -1,7 +1,7 @@
 # Super Simple Time Tracker
 Multi-purpose time trackers for your notes!
 
-![A screenshot of the plugin in action, where you can see an active time tracker for a project](https://raw.githubusercontent.com/Ellpeck/ObsidianSimpleTimeTracker/master/screenshot.png)
+![A screenshot of the plugin in action, where you can see an active time tracker for a project](https://raw.githubusercontent.com/Ellpeck/ObsidianSimpleTimeTracker/master/screenshot.jpg)
 
 # 🤔 Usage
 To get started tracking your time with Super Simple Time Tracker, open up the note that you want to track your time in. Move the cursor to the area you want the tracker to reside in, and then open your command palette and execute the `Super Simple Time Tracker: Insert Time Tracker` command.