doc: Add documentation-generating scripts to the Crashpad tree

tools/man_footer.ad

-// Copyright 2014 The Crashpad Authors. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-== Resources
-
-Crashpad home page: https://crashpad.googlecode.com/.
-
-Report bugs at https://code.google.com/p/crashpad/issues/entry.
-
-== Copyright
-
-Copyright 2014
-https://chromium.googlesource.com/crashpad/crashpad/+/master/AUTHORS[The
-Crashpad Authors].
-
-== License
-
-Licensed under the Apache License, Version 2.0 (the “License”);
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-[subs="macros"]
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an “AS IS” BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.