Add AUTHORS file.

AUTHORS

+This file maintains the list of present and past declearn authors.
+A secondary file listing punctual open-source contributors may complement it.
+
+Declearn 2.0 (new implementation)
+- Paul Andrey (core developer)
+- Nathan Bigaud (core developer)
+- Nathalie Vauquier (supervision)
+
+Declearn 1.x (continuation of 1.0)
+- Nathalie Vauquier
+- Marc-André Sirgiel
+
+Declearn 1.0
+- Yannick Bouillard (core developer)
+- Paul Andrey (review and minor contributions)
+
+Supervision (all versions)
+- Marc Tommasi
+- Aurélien Bellet

README.md

@@ -870,8 +870,17 @@ of merge requests.
 Declearn is an open-source software developed by people from the
 [Magnet](https://team.inria.fr/magnet/) team at [Inria](https://www.inria.fr/).
 
-It is distributed under the Apache-2.0 license. All code files should therefore
-contain the following mention, which also applies to the present README file:
+### Authors
+
+Current core developers are listed under the `pyproject.toml` file. A more
+detailed acknowledgement and history of authors and contributors to declearn
+can be found in the `AUTHORS` file.
+
+### License
+
+Declearn distributed under the Apache-2.0 license. All code files should
+therefore contain the following mention, which also applies to the present
+README file:
 ```
 Copyright 2023 Inria (Institut National de la Recherche en Informatique
 et Automatique)

pyproject.toml

@@ -16,11 +16,10 @@ license = {file = "LICENSE"}
 authors = [
     {name = "Paul Andrey", email = "paul.andrey@inria.fr"},
     {name = "Nathan Bigaud", email = "nathan.bigaud@inria.fr"},
-    {name = "Nathalie Vauquier", email = "nathalie.vauquier@inria.fr"},
 ]
 maintainers = [
     {name = "Paul Andrey", email = "paul.andrey@inria.fr"},
-    {name = "Nathalie Vauquier", email = "nathalie.vauquier@inria.fr"},
+    {name = "Nathan Bigaud", email = "nathan.bigaud@inria.fr"},
 ]
 classifiers = [
     "Development Status :: 5 - Production/Stable",