The 1.18.0 release of yamllint has started linting its .yamllint
config file by default. Add a document marker at the top of the file
so that it will pass document-start rule.
# Copyright (c) 2018 mudpy authors. Permission to use, copy,
# modify, and distribute this software is granted under terms
# provided in the LICENSE file distributed with this software.
# Copyright (c) 2018 mudpy authors. Permission to use, copy,
# modify, and distribute this software is granted under terms
# provided in the LICENSE file distributed with this software.