Convert and rename AUTHORS to AUTHORS.md

Author: flashcode

AUTHORS

@@ -0,0 +1,28 @@
+<!--
+SPDX-FileCopyrightText: 2011-2025 Sébastien Helleu <[email protected]>
+
+SPDX-License-Identifier: GPL-3.0-or-later
+-->
+
+# QWeeChat authors
+
+## Developers
+
+- General code
+  - [Sébastien Helleu](https://github.com/flashcode) (FlashCode)
+
+## Contributors
+
+Alphabetically:
+
+- Abhilash Raj
+- Florian Besser (Banton)
+- Gryllida A (gry)
+- howaboutudance
+
+## Contact
+
+Developers are connected to IRC:
+
+- server: irc.libera.chat
+- channels: #weechat (English) and #weechat-fr (French)

AUTHORS.md

@@ -8,7 +8,6 @@ version = 1
 path = [
     ".gitignore",
     ".mailmap",
-    "AUTHORS",
     "CHANGELOG.md",
     "MANIFEST.in",
     "README.md",