fmics21: minor change in README title

README.md

-Frama-C Verification of Paparazzi
-=================================
+Formal verification of the Paparazzi autopilot
+==============================================
 
 This GitLab repository is a fork of Paparazzi UAV autopilot repository
 (https://github.com/paparazzi/paparazzi). The aim of this project is
@@ -28,7 +28,7 @@ _statement contracts_ are used in the proofs, but this feature
 has been removed in newer versions.
 
 How to launch the verification process
--------------
+--------------------------------------
 
 First, go to the `sw/airborne` directory: