Use the official markdown version of the GPLv3

Add myself to AUTHORS.md

Change-Id: I5893057d60fa76981ab256ee78822e78f7c60870
diff --git a/AUTHORS.md b/AUTHORS.md
index 42052b0..5c29bdf 100644
--- a/AUTHORS.md
+++ b/AUTHORS.md
@@ -12,3 +12,5 @@
 The following is an inevitably incomplete list of MUCH-APPRECIATED CONTRIBUTORS,
 people who have reported bugs, submitted patches, and implemented new features
 in the library:
+
+* Davide Pesavento       <https://www.linkedin.com/in/davidepesavento>