docs(getting-started): fix logo for Cube Core (#6383)

Author: hassankhan

docs/content/Getting-Started/Overview.mdx

@@ -24,7 +24,7 @@ Alternatively, you can run Cube on your own infrastructure.
   />
   <GridItem
     url="getting-started/core/overview"
-    imageUrl="https://raw.githubusercontent.com/cube-js/cube.js/master/docs/static/icons/git.svg"
+    imageUrl="https://raw.githubusercontent.com/cube-js/cube.js/master/docs/static/icons/docker.svg"
     title="Cube Core"
   />
 </Grid>