adjust header

doc/environments/groupthm/groupthm.dtx

@@ -1,8 +1,8 @@
 % \iffalse meta-comment
 %
-%% File: l3prop.dtx
+%% File: groupthm.dtx
 %
-% Copyright (C) 1990-2022 The LaTeX Project
+% Copyright (C) 2022 Maximilian Keßler
 %
 % It may be distributed and/or modified under the conditions of the
 % LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -11,17 +11,8 @@
 %
 %    https://www.latex-project.org/lppl.txt
 %
-% This file is part of the "l3kernel bundle" (The Work in LPPL)
-% and all files in that bundle must be distributed together.
-%
 % -----------------------------------------------------------------------
 %
-% The development version of the bundle can be found at
-%
-%    https://github.com/latex3/latex3
-%
-% for those people who are interested.
-%
 %<*driver>
 \documentclass[full,kernel]{l3doc}
 \usepackage{mkessler-todo}