[ADD] .editorconfig [ci skip]

.editorconfig

@@ -0,0 +1,20 @@
+# Configuration for known file extensions
+[*.{css,js,json,less,md,py,rst,sass,scss,xml,yaml,yml}]
+charset = utf-8
+end_of_line = lf
+indent_size = 4
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[.eslintrc,*.{json,yml,yaml,rst,md}]
+indent_size = 2
+
+# Do not configure editor for libs and autogenerated content
+[*/static/{lib,src/lib}/**,*/static/description/index.html,*/readme/../README.rst]
+charset = unset
+end_of_line = unset
+indent_size = unset
+indent_style = unset
+insert_final_newline = false
+trim_trailing_whitespace = false