docs: deploy docs to production server from CI

docs/build_docs.py

@@ -9,6 +9,20 @@
 #
 # Specific custom docs functionality should be added in conf_common.py or in a Sphinx extension, not here.
 #
+# Copyright 2020 Espressif Systems (Shanghai) PTE LTD
+#
+# 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.
+#
 from __future__ import print_function
 import argparse
 import locale