readme: swap doxygen/sphinx badges

Prefer Sphinx as the first entry.

Signed-off-by: Gerard Marull-Paretas <[email protected]>

Author: gmarull

README.md

@@ -1,11 +1,11 @@
 # Zephyr Example Application
 
-<a href="https://zephyrproject-rtos.github.io/example-application/doxygen">
-  <img alt="API Documentation" src="https://img.shields.io/badge/API-documentation-3D578C?logo=c&logoColor=white">
-</a>
 <a href="https://zephyrproject-rtos.github.io/example-application/sphinx">
   <img alt="Documentation" src="https://img.shields.io/badge/documentation-3D578C?logo=sphinx&logoColor=white">
 </a>
+<a href="https://zephyrproject-rtos.github.io/example-application/doxygen">
+  <img alt="API Documentation" src="https://img.shields.io/badge/API-documentation-3D578C?logo=c&logoColor=white">
+</a>
 
 This repository contains a Zephyr example application. The main purpose of this
 repository is to serve as a reference on how to structure Zephyr-based