Fixed #26124 -- Added missing code formatting to docs headers.

docs/howto/custom-management-commands.txt

docs/howto/deployment/wsgi/apache-auth.txt

docs/howto/deployment/wsgi/modwsgi.txt

docs/howto/windows.txt

docs/ref/checks.txt

docs/ref/class-based-views/base.txt

docs/ref/class-based-views/flattened-index.txt

docs/ref/class-based-views/generic-date-based.txt

docs/ref/class-based-views/generic-display.txt

docs/ref/class-based-views/generic-editing.txt

docs/ref/class-based-views/mixins-date-based.txt

docs/ref/class-based-views/mixins-editing.txt

docs/ref/class-based-views/mixins-multiple-object.txt

docs/ref/class-based-views/mixins-simple.txt

docs/ref/class-based-views/mixins-single-object.txt

docs/ref/clickjacking.txt

docs/ref/contrib/admin/index.txt

docs/ref/contrib/auth.txt

docs/ref/contrib/gis/commands.txt

docs/ref/contrib/gis/functions.txt