docs: switch to agpl license

src/imap/envelope/cli.rs

@@ -1,3 +1,20 @@
+// This file is part of Himalaya, a CLI to manage emails.
+//
+// Copyright (C) 2022-2026 soywod <pimalaya.org@posteo.net>
+//
+// This program is free software: you can redistribute it and/or modify it under
+// the terms of the GNU Affero General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option) any
+// later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
 use anyhow::Result;
 use clap::Subcommand;
 use pimalaya_cli::printer::Printer;