refactor(docs): move from reST to Markdown (reanahub#195)

Convert docs from reStructuredText to Markdown so that the changelog
file is compatible with Release Please.

AUTHORS.md

@@ -0,0 +1,21 @@
+# Authors
+
+The list of contributors in alphabetical order:
+
+- [Adelina Lintuluoto](https://orcid.org/0000-0002-0726-1452)
+- [Agisilaos Kounelis](https://orcid.org/0000-0001-9312-3189)
+- [Audrius Mecionis](https://orcid.org/0000-0002-3759-1663)
+- [Clemens Lange](https://orcid.org/0000-0002-3632-3157)
+- [Diego Rodriguez](https://orcid.org/0000-0003-0649-2002)
+- [Domenic Gosein](https://orcid.org/0000-0002-1546-0435)
+- [Elena Gazzarrini](https://orcid.org/0000-0001-5772-5166)
+- [Giuseppe Steduto](https://orcid.org/0009-0002-1258-8553)
+- [Marco Donadoni](https://orcid.org/0000-0003-2922-5505)
+- [Marco Vidal](https://orcid.org/0000-0002-9363-4971)
+- [Maria Fernando](https://github.com/MMFernando)
+- [Michael Eliachevitch](https://orcid.org/0000-0003-2033-537X)
+- [Parth Shandilya](https://github.com/ParthS007)
+- [Rokas Maciulaitis](https://orcid.org/0000-0003-1064-6967)
+- [Sinclert Perez](https://www.linkedin.com/in/sinclert)
+- [Tibor Simko](https://orcid.org/0000-0001-7202-5803)
+- [Vladyslav Moisieienkov](https://orcid.org/0000-0001-9717-0775)