Updated Andre Belem in AUTHORS.md (#1974)

Author: andrebelem

AUTHORS.md

@@ -9,6 +9,7 @@ The following people have contributed code and/or documentation to the project
 (alphabetical by name) and are considered to be "PyGMT Developers":
 
 * [Abhishek Anant](https://twitter.com/itsabhianant) | [0000-0002-5751-2010](https://orcid.org/0000-0002-5751-2010) | Unaffiliated
+* [Andre L. Belem](https://github.com/andrebelem) | [0000-0002-8865-6180](https://orcid.org/0000-0002-8865-6180) | Fluminense Federal University, Brazil
 * [Dongdong Tian](https://seisman.info/) | [0000-0001-7967-1197](https://orcid.org/0000-0001-7967-1197) | China University of Geosciences, China
 * [Jamie Quinn](http://jamiejquinn.com) | [0000-0002-0268-7032](https://orcid.org/0000-0002-0268-7032) | University College London, United Kingdom
 * [Jiayuan Yao](https://github.com/core-man) | [0000-0001-7036-4238](https://orcid.org/0000-0001-7036-4238) | Nanyang Technological University, Singapore