Update README.md

Author: generall

README.md

@@ -1,5 +1,9 @@
 <p align="center">
-  <img height="120" src="https://github.com/qdrant/qdrant/raw/master/docs/logo.svg" alt="Qdrant">
+  <picture>
+      <source media="(prefers-color-scheme: dark)" srcset="https://github.com/qdrant/qdrant/raw/master/docs/logo-dark.svg">
+      <source media="(prefers-color-scheme: light)" srcset="https://github.com/qdrant/qdrant/raw/master/docs/logo-light.svg">
+      <img height="100" alt="Qdrant" src="https://github.com/qdrant/qdrant/raw/master/docs/logo.svg">
+  </picture>
   &nbsp;
   <img height="150" width="100" src="./resources/java-logo-small.svg" alt="Java">