Add .editorconfig (apache#117)

.editorconfig

@@ -0,0 +1,47 @@
+# -*- coding: utf-8 -*-
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+root = true
+
+[*]
+end_of_line = lf
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+charset = utf-8
+
+[*.py]
+indent_size = 4
+
+[*.sh]
+indent_size = 4
+
+[*.js]
+indent_size = 2
+
+[*.{css,scss}]
+indent_size = 2
+
+[*.{md,rst}]
+indent_size = 2
+
+[*.{yml,yaml}]
+indent_size = 2
+
+[*.{htm,html}]
+indent_size = 4