Adding branded version of mindmap. higher quality (PNG instead of JPG) (#343)

Author: spier

book/explore-patterns.md

@@ -6,7 +6,7 @@ Now how to make it easy for readers to discover the patterns that can help them
 
 For this purpose we provide this mind map. It **categorizes patterns based on the different phases of an InnerSource Program**, and the challenges that might appear in the respective phases.
 
-<img src="./innersource-program-mind-map.jpg" title="InnerSource Patterns as a Mind Map">
+<img src="./innersource-program-mind-map.png" title="InnerSource Patterns as a Mind Map">
 
 ## Improve this Mind Map
 

book/innersource-program-mind-map.jpg

@@ -14,7 +14,7 @@ Instead edit toc_template.md
 * [Explore Patterns](../book/explore-patterns.md)
 * [Contribute to this book](../book/contribute.md)
 
-<img src="./innersource-program-mind-map.jpg" title="InnerSource Patterns as a Mind Map">
+<img src="./innersource-program-mind-map.png" title="InnerSource Patterns as a Mind Map">
 
 ## Patterns <a id="p"></a>