Update banner (#961) (#962)

* Update banner

Signed-off-by: Pablo Garrido <pablogs9@gmail.com>

* update

Signed-off-by: Pablo Garrido <pablogs9@gmail.com>
(cherry picked from commit bfc99de)

Co-authored-by: Pablo Garrido <pablogs9@gmail.com>

Author: mergify[bot]

.images/arduino_logo.png

@@ -1,12 +1,5 @@
-<br/>
-
-<a>
-   <p align="center">
-      <img width="20%" src=".images/arduino_logo.png">
-      <img width="40%" src=".images/microros_logo.png">
-   </p>
-</a>
-<br/>
+![banner](.images/banner-dark-theme.png#gh-dark-mode-only)
+![banner](.images/banner-light-theme.png#gh-light-mode-only)
 
 # micro-ROS for Arduino