Add snippet for the AGPL header

snippets/python-mode/agpl_header

@@ -0,0 +1,19 @@
+# -*- mode: snippet -*-
+# name: agpl-header
+# key: agpl
+# --
+# ${1:project_name}
+# Copyright (C) ${2:year}  ${3:author_name}
+#
+# 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/>.