Add inverted logo for dark mode

Author: marcphilipp

README.md

@@ -1,4 +1,8 @@
-# <img src="https://junit.org/assets/img/junit-logo.svg" width="200" alt="JUnit"/>
+<h1><picture width="200">
+ <source media="(prefers-color-scheme: dark)" srcset="https://junit.org/assets/img/junit-logo-inverted.svg">
+ <source media="(prefers-color-scheme: light)" srcset="https://junit.org/assets/img/junit-logo.svg">
+ <img alt="JUnit" src="https://junit.org/assets/img/junit-logo.svg" width="200">
+</picture></h1>
 
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