fix(README): mismatched picture tags (apache#25739)

README.md

@@ -186,7 +186,7 @@ Understanding the Superset Points of View
   - [Helm Chart](https://github.com/apache/superset/tree/master/helm/superset)
 
 - Recordings of Past [Superset Community Events](https://preset.io/events)
-  - [Mixed Time Series Charts](https://preset.io/events/mixed-time-series-visualization-in-superset-workshop/)  
+  - [Mixed Time Series Charts](https://preset.io/events/mixed-time-series-visualization-in-superset-workshop/)
   - [How the Bing Team Customized Superset for the Internal Self-Serve Data & Analytics Platform](https://preset.io/events/how-the-bing-team-heavily-customized-superset-for-their-internal-data/)
   - [Live Demo: Visualizing MongoDB and Pinot Data using Trino](https://preset.io/events/2021-04-13-visualizing-mongodb-and-pinot-data-using-trino/)
 	- [Introduction to the Superset API](https://preset.io/events/introduction-to-the-superset-api/)